Exodus 12:15

12:15 For seven days you must eat bread made without yeast. Surely on the first day you must put away yeast from your houses because anyone who eats bread made with yeast from the first day to the seventh day will be cut off from Israel.

Exodus 13:7

13:7 Bread made without yeast must be eaten for seven days; no bread made with yeast shall be seen among you, and you must have no yeast among you within any of your borders.

Exodus 34:25

34:25 “You must not offer the blood of my sacrifice with yeast; the sacrifice from the feast of Passover must not remain until the following morning.