שולחן ערוך · אורח חיים

The conduct on rising — Seif 1: A person should strengthen himself like a lion to rise in the morning for the service of his Creator, so that he himself awakens the dawn rather than being awakened by it.

Rama's gloss: In any case, one should not delay past the time at which the community prays.

Rama's gloss (the yesod): «I have set the Lord before me always» is a great principle of the Torah — a person's conduct when alone at home is not like his conduct before a great king; and all the more so when he sets to his heart that the Holy One, blessed be He, whose glory fills the earth, stands over him and sees his deeds.

And immediately upon awakening from his sleep he should rise with alacrity to the service of his Creator.