Exodus 13:6
TSK
For seven days you must eat bread made without yeast, and on the seventh day there is to be a festival to the LORD.
TSK
Treasury of Scripture Knowledge references in NET.
For seven days you must eat bread made without yeast, and on the seventh day there is to be a festival to the LORD.
“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.
You must eat bread made without yeast for six days. The seventh day you are to hold an assembly for the LORD your God; you must not do any work on that day.