Siman 99 — One May Not Nullify a Prohibition Deliberately
The bones that combine, ein mevatlin issur lechatchila, chozer veni'or — to discover and understand
יורה דעה · סימן צ״ט
דין העצמות וביטול איסור לכתחילה
🌱 Introduction Level · מתחילים
✦ ❖ ✦
A first approach to Siman 99: the 7 seifim of the Mehaber and the glosses of the Rama, the Hebrew text with a fluent English translation. Do the bones of the prohibition combine with the permitted to nullify it? The rule אין מבטלין איסור לכתחילה (one may not nullify a prohibition deliberately; shogeg / mezid), the חוזר וניעור (the nullified prohibition that "reawakens"), how to assess the mixture (rotev, kipa, min bemino) and the mashehu absorbed in a vessel used abundantly.
Topic: The bones that combine, nullifying a prohibition, shogeg / mezid, chozer veni'or Source: שולחן ערוך יורה דעה סימן צ״ט
Compiled by: הרב יוסף חיים סממה DAAT · daattorah.com
📑 Study outline
1.The text of the Mehaber: the 7 seifim, by thematic groups
2.Context: why this siman deals with bones and nullification
3.The key concepts: atsamot mitztarfin, ein mevatlin, shogeg / mezid, chozer veni'or, min bemino…
4.The assessment: the rotev / kipa / min bemino table
5.The Shach and the Taz: who they are, a few key entries
6.The gloss of the Rama (הגה)
7.Ein mevatlin issur lechatchila: shogeg, mezid and chozer veni'or
8.Modern practical cases: adding permitted food, a nullified mixture, a vessel
9.Summary and comprehension questions
1. The text of the Mehaber — the 7 seifim
Siman 99 continues the laws of תערובת (mixtures of prohibited and permitted food). After the simanim on nullification by sixty (notably 98), the Mehaber (Rabbi Yossef Karo) deals here with two major topics: first, the bones (עצמות) — do they combine with the permitted to reach sixty, or rather with the prohibition? Then the great rule one may not nullify a prohibition deliberately (אין מבטלין איסור לכתחילה), with its consequences (shogeg / mezid), the chozer veni'or (a nullified prohibition that reawakens), and the case of the mashehu absorbed in a vessel. The Rama (Rabbi Moshe Isserles) adds his glosses (הגה) for Ashkenazi practice. Let us explore the seifim by groups.
Group A — The bones combine: raw or already cooked (seifim 1-2)
Seif 1 — The bones of the prohibition combine with the permitted
A piece of nevila containing meat and bones, which fell into a pot of permitted food: the bones of the prohibition combine with the permitted to nullify the prohibition (עצמות האיסור מצטרפים עם ההיתר), and all the more so the bones of the permitted combine with the permitted. But the marrow (מוח) in the bones of the prohibition combines with the prohibition. And the body of the pot (גוף הקדירה) combines neither with the prohibition nor with the permitted. Gloss of the Rama: some are stringent not to combine the bones of the prohibition with the permitted; but in case of loss (הפסד) one relies on the lenient ones who permit — for that is the essential view (כי כן עיקר).
The central idea: bones are not themselves "edible meat": they are therefore counted on the side of the permitted to reach sixty. But what is nourishing — the marrow — stays on the side of the prohibition, and the metal of the pot counts on neither side. The Rama notes a stringent opinion (not to combine the prohibition's bones), but rules that the essential view is lenient, relied upon especially in case of loss.
Seif 2 — Raw combines with the permitted, already cooked combines with the prohibition
All this (the bones of the prohibition combining with the permitted) applies only when the piece of nevila fell into the pot of permitted food raw (חַי). But if it was cooked first by itself, and then fell into the pot of permitted food → its bones combine with the prohibition (עצמות שבה מצטרפים עם האיסור), because they absorbed nevila meat when it cooked alone.
The pivot of the seif: the "neutral" bone (which leans toward the permitted) is only so as long as it absorbed nothing. If the piece of prohibition has already cooked by itself, its own bones have drunk the nevila juice: they are now saturated with prohibition and shift to the side of the prohibition. Raw → side of the permitted; already cooked alone → side of the prohibition.
Group B — Other prohibitions and how to assess (seifim 3-4)
Seif 3 — The absorbed piece combines; the Rama: chatikha naasit nevila
In other prohibitions, except meat-and-milk, a piece absorbed with prohibition (חתיכה הבלועה מאיסור) combines to nullify the prohibition: the piece of permitted food that absorbed a prohibition, being itself permitted matter, may be counted on the side of the permitted. Gloss of the Rama:we do not act this way (ואין נוהגין כן), because we hold that "the piece becomes nevila" (חתיכה נעשית נבילה) for all prohibitions, as stated above in Siman 92.
The point of disagreement: for the Mehaber, a piece of permitted food that absorbed prohibition remains "permitted" and combines toward sixty. For the Rama (Ashkenazi practice), such a piece has itself become a full prohibition — חתיכה נעשית נבילה — and therefore cannot be counted on the side of the permitted. This is exactly the machloket already met in Siman 92.
Seif 4 — How to assess: rotev, kipa, min bemino, kala mechamat ha-or
One assesses with the broth (רוטב), the kipa — the fine particles of meat and spices that gather at the bottom of the pot — and the pieces. One assesses the permitted and the prohibition as they are before us (כמו שבא לפנינו), even though there was more permitted food at the start and it diminished during cooking and was absorbed into the pot. And this is in min beshe-eino mino (different species). But in min bemino (same species), one assesses also what the pot absorbed and what stands in its walls; one estimates it well and views it as if it were present (כאילו הוא בעין). However, what was consumed and lost by the fire (כלה ואבד מחמת האור) does not combine, for it is entirely gone.
כמו שבא לפנינו — "as it presents itself before us": one assesses the prohibition-to-permitted ratio according to the current state of the pot, without reconstructing what was there originally — one does not presume a larger prohibition than appears (achzukei issura lo machzekinan).
Group C — One may not nullify a prohibition deliberately (seifim 5-6)
Seif 5 — Ein mevatlin issur lechatchila; shogeg / mezid
One may not nullify a prohibition deliberately (אין מבטלין איסור לכתחלה); even if it fell into permitted food that does not have the measure to nullify it, one does not add permitted food in order to nullify it. If one transgressed and nullified it, or added: by accident (בשוגג) → permitted; deliberately (במזיד) → prohibited for the one who nullified (if it is his) and for the one for whom it was nullified — and it is forbidden to sell it to another Jew either, so that they not benefit from the nullification (Issur ve-Hetter ha-Aroch, kelal 24) — but for any other person, it is permitted. Gloss of the Rama: and this only if the mixture is dry in dry (יבש ביבש), or even liquid in liquid (לח בלח) according to the view that does not say chatikha naasit nevila (Siman 92); but a piece that absorbed a prohibition — the later addition of permitted food does not help, since we say chatikha naasit nevila (Rashba). And some say that even where one does not say chnn, the addition only helps if it was made before the mixture became known (קודם שנודע); but if it was known before, the later addition does not help — accordingly the Sage who rules would have to investigate whether the permitted was added after it became known (Issur ve-Hetter ha-Aroch, kelal 37); but the practice is not so (ולא נהגו כן).
The practical heart of the siman: one never "manufactures" a nullification. As long as sixty is lacking, one does not add permitted food to make it up. If one nullified anyway: the consequence depends on the intent. Shogeg (unwittingly, or by a mistake of fact) → permitted; mezid (knowingly) → the prohibition remains, but only for the offender and for the one he aimed to benefit; third parties may benefit, and it is forbidden to resell it to a Jew to circumvent this.
A rabbinic prohibition (דרבנן): one does not mix it by hand to nullify it, and if one did so deliberately (במזיד) → prohibited; but if it fell by itself and there is not enough to nullify it → one adds (מרבה עליו) and nullifies it. Gloss of the Rama: some say that one does not nullify a rabbinic prohibition nor add to it, just as a Torah prohibition — and such is the practice, one does not deviate. — The chozer veni'or: a prohibition that has been nullified (there was sixty against it), to which one then adds from the original prohibition (מן האיסור הראשון) → it "reawakens" (חוזר וניעור) and becomes prohibited again, whether min bemino or min beshe-eino mino, dry or liquid, whether it became known in the meantime or not. — But a kazayit of cheilev that fell into water and was nullified in sixty, then fell from the water into a meat pot → permitted, even if there is not sixty in the meat against the cheilev, since it was already nullified in the water; and any similar case.
Two opposite movements:חוזר וניעור = one adds of the same original prohibition to an already-nullified mixture → the total again exceeds the threshold → the prohibition "reawakens." Conversely, an already-nullified prohibition that migrates to a new permitted item (cheilev: water → meat pot) does not reawaken: having been nullified once in the water, it stays nullified even where there would not be sixty.
Group D — The mashehu absorbed in a vessel (seif 7)
Seif 7 — A vessel used abundantly (permitted) vs at small amounts (prohibited)
If a small amount of prohibition was absorbed into a kosher vessel: if the way of that vessel is to be used with abundance (בשפע) of permitted food → it is permitted to use it lechatchila, since the prohibition is minimal and cannot come to impart taste (אי אפשר לבא לידי נתינת טעם). Therefore, a mashehu of prohibition absorbed in a pot, in jugs (קנקנים) and the like → it is permitted to use them lechatchila, even ben yomo (used within the day), since it is impossible to come to impart taste. But if it is absorbed in a vessel that is sometimes used with a small amount, such as a bowl (כקערה) → it is forbidden to use it, even with abundance, by decree (גזירה) lest one use it with a small amount and it come to impart taste.
Everything depends on the vessel's usage. A mashehu (the most minute trace) of prohibition absorbed in a vessel always used in large quantity (pot, jug) can never impart taste: permitted lechatchila, even one less than 24 hours old. But a vessel sometimes used with a small amount (a bowl) is forbidden by gezeira — a precaution lest one day the amount be small enough for the taste to emerge.
2. Context — where this siman fits
The preceding simanim laid down the rules of nullification by sixty (98) and of חתיכה נעשית נבילה (92). Siman 99 refines two very practical questions: against what does one count the sixty (do bones count? marrow? the pot? the reduced broth?), and is one allowed to bring about a nullification (אין מבטלין איסור לכתחילה)? It adds the delicate chozer veni'or and the leniency of the mashehu in a vessel used abundantly.
The major questions of the siman
Question
Where?
Typical answer
Do the bones combine, and the marrow?
Seifim 1-2
Bones of prohibition → permitted side; marrow → prohibition side; raw vs cooked
Does the absorbed piece combine?
Seif 3
Mehaber: yes; Rama: no (chatikha naasit nevila)
How to assess the mixture
Seif 4
kemo sheba lefaneinu; min bemino → also the absorbed; kala mechamat ha-or doesn't count
Nullifying deliberately and shogeg / mezid
Seifim 5-6
ein mevatlin; shogeg permitted / mezid prohibited; chozer veni'or
The mashehu in a vessel
Seif 7
be-shefa → permitted lechatchila; small amount (bowl) → prohibited gezeira
The cross-cutting idea: everything is a matter of measure (sixty) and of an honest count. What does one count on the permitted side (bones, broth, kipa, what is absorbed in the walls)? What stays on the prohibition side (marrow, an absorbed piece per the Rama)? And, above all, one never "rigs" the result: ein mevatlin issur lechatchila.
3. The key concepts of this siman
To understand Siman 99, one must master a small technical vocabulary describing what combines, how one assesses, and the rule against deliberate nullification.
עצמות מצטרפין — The bones combine: bones, being inedible, are not counted "as prohibition" → they are placed on the side of the permitted to reach sixty. But the marrow (מוח), being nourishing, stays on the prohibition side (seif 1).
גוף הקדירה — The body of the pot: the metal of the pot that is now cooking the prohibition and the permitted combines with neither one (seif 1). It is neutral in the count.
קיפה — Kipa: the fine particles of meat and spices that gather at the bottom of the pot. They are included in the count of permitted and prohibition (seif 4).
מין במינו / מין בשאינו מינו — Same species / different species: in min beshe-eino mino, one assesses what one sees (kemo sheba lefaneinu); in min bemino, since the taste is not distinguishable, one assesses also what is absorbed in the walls (ke-ilu hu be-ein) (seif 4).
אין מבטלין איסור לכתחילה — One may not nullify a prohibition deliberately: one does not bring about a nullification and does not add permitted food to reach sixty. Shogeg → permitted; mezid → prohibited (for the one who nullified and the one for whom) (seif 5).
שוגג / מזיד — Unwitting / deliberate: it is the intent that decides the fate of a brought-about nullification. Inadvertently, the mixture stays permitted; knowingly, it is prohibited for the one who acted and his beneficiary (seif 5).
חוזר וניעור — Chozer veni'or: "it reawakens." A prohibition already nullified in sixty becomes prohibited again if one adds of the same original prohibition and the total again crosses the threshold (seif 6).
The mashehu (seif 7): the minute trace of prohibition absorbed in a vessel always used abundantly can never impart taste → permitted lechatchila; but a vessel sometimes used with a small amount is forbidden by גזירה.
4. The assessment — the rotev / kipa / min bemino table
Seifim 1, 2 and 4 boil down to a table. One crosses what is at stake with on which side it counts.
Element
Combines with…
Remark
Bones of the prohibition (raw piece)
🟢 The permitted
Inedible → heter side (seif 1)
Marrow (מוח) in the prohibition's bones
🔴 The prohibition
Nourishing (seif 1)
Bones of a piece cooked alone first
🔴 The prohibition
They absorbed nevila juice (seif 2)
Body of the pot (גוף הקדירה)
⚪ Neither
Neutral (seif 1)
Broth (רוטב), kipa, pieces
🟢 They count
kemo sheba lefaneinu (seif 4)
Absorbed in the walls — in min bemino
🟢 One estimates it
ke-ilu hu be-ein (seif 4)
What is consumed by the fire (kala mechamat ha-or)
⚪ Does not count
Entirely gone (seif 4)
The logic in one sentence: one places on the permitted side everything that is not truly consumable prohibition (bones, broth, kipa, still-present absorbed matter), on the prohibition side what is saturated with it (marrow, already-cooked bones), and one counts neither the neutral metal nor what the fire made disappear.
The point of the honest count (seif 4): one assesses according to the current state — כמו שבא לפנינו — without artificially inflating the prohibition. This is the same spirit as seif 5: one does not manipulate the mixture to obtain the desired result.
5. The Shach and the Taz — the great commentators
In Yoreh De'ah, the Shulchan Aruch is never read alone. Two great commentaries accompany it on every page and structure practical study: the Shach and the Taz. These are the reference nosei kelim in Yoreh De'ah (no Mishna Berura here, which only comments on Orach Chaim).
The Shach (ש״ך) — abbreviation of שפתי כהן, Siftei Kohen, by Rabbi Shabtai haCohen (Lithuania, 17th century). It is the reference commentary on Yoreh De'ah, of great analytical depth.
The Taz (ט״ז) — abbreviation of טורי זהב, Turei Zahav, by Rabbi David haLevi Segal (Poland, 17th century). Often in dialogue — and sometimes in disagreement — with the Shach.
A key entry from the Taz
Taz s.k. 1 — Why the bones combine with the permitted
The Taz explains why the bones are placed on the permitted side: because bones are not fit for consumption and are not part of the prohibition itself; moreover, their moisture dilutes the prohibition. The marrow, by contrast — edible, whose fat is absorbed — combines with the prohibition. The Taz also links this to the Rama's gloss in Siman 98 on bones already saturated.
The Shach refines a distinction: soft bones, which contain marrow and moisture, combine with the prohibition; but hard, dry bones, as well as eggshells, even of the prohibition, combine with the permitted (Raah, Ran, Or Zaroua, Bach). The Pitchei Teshuva (s.k. 1) reports that the Shach rules like the Ran and notes the dissenters (a debate of cooking / salting, lean / fatty).
One sees the method: the Shach and the Taz do not repeat the Mehaber — they explain the mechanism (why a bone leans one way or the other: edibility, moisture, marrow) and refine (soft / dry bones). This is exactly what one delves into at the Lamdan level.
6. The gloss of the Rama (הגה)
The Rama (Rabbi Moshe Isserles) adds to the Mehaber's text glosses that reflect Ashkenazi practice and specify the practical halacha. Here are his most notable interventions in our siman.
On seif 1 — a stringent opinion on bones, but leniency is the essential view
Gloss of the Rama: ויש מחמירים שלא לצרף עצמות האיסור עם ההיתר לבטל; ובמקום הפסד יש לסמוך אמקילין ומתירין כי כן עיקר — "some are stringent not to combine the bones of the prohibition with the permitted; but in case of loss, one relies on the lenient ones who permit, for that is the essential view". The Rama notes the stringent position while ruling that the core of the law is lenient.
On seif 3 — chatikha naasit nevila for all prohibitions
Gloss of the Rama: ואין נוהגין כן כי קיימא לן בכל איסורים חתיכה נעשית נבילה כדלעיל סימן צ״ב — "we do not act this way, for we hold chatikha naasit nevila for all prohibitions, as above in Siman 92". Where the Mehaber counts the absorbed piece on the permitted side, the Rama considers it a full prohibition, which therefore does not combine.
On seif 5 — the addition of permitted food and the nodaa / lo nodaa debate
Gloss of the Rama: ודוקא שנתערב יבש ביבש או אפילו לח בלח… אבל חתיכה שבלעה איסור לא מהני שנתוסף אחר כך ההיתר… ולא נהגו כן — the addition of permitted food only works for dry in dry or liquid in liquid (per the view that does not hold chnn), not for a piece that absorbed prohibition. Some further require that the addition precede the awareness of the mixture (kodem she-noda) — but the Rama concludes: "the practice is not so" (ולא נהגו כן).
On seif 6 — not nullifying even a rabbinic prohibition; the chozer veni'or
Gloss of the Rama: ויש אומרים דאין לבטל איסור דרבנן או להוסיף עליו… וכן נוהגין ואין לשנות — one does not nullify even a rabbinic prohibition, and such is the practice. Then he sets out the chozer veni'or: a prohibition nullified in sixty, to which one adds of the original prohibition, reawakens — dry or liquid, same species or not, known in the meantime or not; but the cheilev nullified in water that then passes into meat does not reawaken.
The Rama carefully distinguishes the basic law (the Mehaber) from the stricter Ashkenazi practice (chnn everywhere, not nullifying even derabbanan, chozer veni'or) — while preserving a targeted leniency for bones in case of loss (seif 1).
7. Ein mevatlin issur lechatchila — shogeg, mezid and chozer veni'or
Seifim 5-6 — the practical heart of the siman — deserve a pause. What exactly does "one may not nullify a prohibition deliberately" mean?
Everything rests on two demands. First, one does not manufacture the nullification: as long as sixty is lacking, one adds nothing. Second, if one acted anyway, the fate depends on the intent:
Shogeg (inadvertently or by a mistake of fact): the mixture stays permitted.
Mezid (knowingly): the prohibition remains for the one who nullified (if it is his) and for the one for whom he did it; but permitted to others, and forbidden to resell it to a Jew to circumvent the rule.
Case
Permitted / prohibited?
For whom?
Nullified in shogeg (by accident)
🟢 Permitted
For all
Nullified in mezid (deliberately)
🔴 Prohibited
For the one who nullified and the one for whom
Mezid — for others
🟢 Permitted
Any other person
Mezid — sale to another Jew
🔴 Forbidden
So as not to benefit from the nullification
Rabbinic derabbanan fell by itself, no 60
🟢 marbeh alav
Mehaber; Rama: do not nullify
Chozer veni'or (adding original prohibition)
🔴 Reawakens
Becomes prohibited again
And seif 6 adds the finishing touch: a nullified prohibition that migrates to a new permitted item (the cheilev: water → meat pot) does not reawaken — it was already nullified once. This is the exact mirror of chozer veni'or: only the addition of the same original prohibition reawakens the mixture.
8. Modern practical cases
How do these rules apply in our kitchens today? Here are three common situations illuminated by our siman.
Case 1 — Adding permitted food to "make up" for a shortfall of sixty
A little prohibition fell into a saucepan, and there is not quite sixty times as much permitted food. The temptation is to add permitted food until sixty is reached. Seif 5 forbids it: ein mevatlin issur lechatchila. If one did it inadvertently (shogeg), the result is permitted; if knowingly (mezid), it remains prohibited for oneself and one's household. For the practical halacha, consult your Rav.
Case 2 — An already-nullified prohibition to which one adds more
A drop of prohibition was nullified in sixty in a large pot; one then adds more of that same prohibition. By the chozer veni'or (seif 6), if the total again crosses the threshold, the prohibition "reawakens" and the mixture becomes prohibited again. By contrast, the already-nullified permitted matter that migrates to another dish stays permitted. For the practical halacha, consult your Rav.
Case 3 — A trace of prohibition absorbed in a pot or a bowl
A mashehu of prohibition was absorbed in a vessel (seif 7). If it is a large pot or a jug, always used abundantly, it is permitted lechatchila, even one less than 24 hours old — never any taste. But if it is a bowl, sometimes used with a small amount, its use is forbidden by gezeira. For the practical halacha, consult your Rav.
The thread running through the three cases: before panicking, ask three questions — against what does one count the sixty (bones, broth, absorbed matter)? is one allowed to act upon the mixture (ein mevatlin)? could the trace ever impart taste? But the concrete decision always belongs to the Rav, who knows the factual details.
9. Summary of Siman 99
The essence of Siman 99 in a few sentences:
The bones of the prohibition combine with the permitted to nullify; the marrow combines with the prohibition; the pot counts on neither side (seif 1).
This applies when the piece fell in raw; if it cooked alone first, its bones absorbed nevila juice → the prohibition side (seif 2).
For other prohibitions, the absorbed piece combines (Mehaber); but the Rama holds chatikha naasit nevila everywhere (seif 3).
One assesses kemo sheba lefaneinu; in min bemino one also counts what is absorbed in the walls; what is consumed by the fire does not count (seif 4).
Ein mevatlin issur lechatchila: one does not add permitted food; shogeg → permitted, mezid → prohibited (for the offender and the one for whom; sale forbidden; permitted to others) (seif 5).
One does not nullify even a rabbinic (derabbanan) prohibition (Rama); the chozer veni'or: adding original prohibition → the prohibition reawakens; but the cheilev nullified that migrates (water → meat) does not reawaken (seif 6).
A mashehu absorbed in a vessel used abundantly (pot, jug) → permitted lechatchila even ben yomo; in a vessel used at a small amount (bowl) → forbidden, gezeira (seif 7).
Memory table
Situation
Rule
Bones of the prohibition (raw piece)
🟢 Permitted side (the marrow stays with the prohibition)
Piece cooked alone first
🔴 Its bones combine with the prohibition
Assessing the mixture
🟡 kemo sheba lefaneinu; min bemino → also the absorbed
Adding permitted food to reach 60
🔴 ein mevatlin issur lechatchila
Nullified shogeg / mezid
🟢 shogeg permitted / 🔴 mezid prohibited
Adding original prohibition (already nullified)
🔴 chozer veni'or — it reawakens
Mashehu in a pot / a bowl
🟢 Pot (be-shefa) / 🔴 Bowl (gezeira)
Comprehension questions
Check your understanding:
Why do the bones of the prohibition combine with the permitted? And the marrow (seif 1)? What about the גוף הקדירה?
What is the difference between a piece that fell in raw and one cooked alone first (seif 2)?
What does the Mehaber hold about the absorbed piece (seif 3)? What does the Rama answer, and on the basis of which principle?
What is כמו שבא לפנינו? What does one additionally assess in מין במינו (seif 4)? What does one not count (kala mechamat ha-or)?
Explain אין מבטלין איסור לכתחילה. What does the intent shogeg / mezid change (seif 5)? For whom does the prohibition remain?
May one nullify a rabbinic (derabbanan) prohibition? What does the Mehaber hold, and the Rama (seif 6)?
What is the חוזר וניעור? Why does the cheilev that migrates (water → meat) not reawaken (seif 6)?
Why is a משהו in a pot permitted lechatchila, and forbidden in a bowl (seif 7)?
What does the Taz (s.k. 1) say about the reason the bones combine? And the Shach (s.k. 1) about soft and dry bones?
What is the link between the spirit of seif 4 (kemo sheba lefaneinu) and that of seif 5 (ein mevatlin)?
To go further
If you wish to delve deeper into this siman:
📚 Level 2 — Lamdan: the pilpul, the yesod of atsamot mitztarfin (soft / dry bones, Shach and Ran), the machloket on chatikha naasit nevila, the mechanism of chozer veni'or (Taz s.k. 13-14), grounded in the sugyot of Chullin
✨ Level 3 — Synthesis: the comparative tables (what combines, shogeg / mezid, chozer veni'or), the rules of thumb and quick memorization of the 7 seifim
⚖️ Level 4 — Halacha lema'aseh: the practical psak (Shach, Taz, Pri Megadim, Pitchei Teshuva) and contemporary poskim on concrete cases
The sources of this level can be consulted on Sefaria: