Exodus 34:18

34:18 “You must keep the Feast of Unleavened Bread. For seven days you must eat bread made without yeast, as I commanded you; do this at the appointed time of the month Abib, for in the month Abib you came out of Egypt.

Exodus 23:15

23:15 You are to observe the Feast of Unleavened Bread; seven days you must eat bread made without yeast, as I commanded you, at the appointed time of the month of Abib, for at that time you came out of Egypt. No one may appear before me empty-handed.