'Unleavened Bread' in the Bible

You shall not eat leavened bread with it; seven days you shall eat with it unleavened bread, the bread of affliction (for you came out of the land of Egypt in haste), so that you may remember all the days of your life the day when you came out of the land of Egypt.

Six days you shall eat unleavened bread, and on the seventh day there shall be a solemn assembly to the Lord your God; you shall do no work on it.

“Three times in a year all your males shall appear before the Lord your God in the place which He chooses, at the Feast of Unleavened Bread and at the Feast of Weeks and at the Feast of Booths, and they shall not appear before the Lord empty-handed.