'Unleavened' in the Bible

Take no leavened bread with it; for seven days let your food be unleavened bread, that is, the bread of sorrow; for you came out of the land of Egypt quickly: so the memory of that day, when you came out of the land of Egypt, will be with you all your life.

For six days let your food be unleavened bread; and on the seventh day there is to be a holy meeting to the Lord your God; no work is to be done.

Three times in the year let all your males come before the Lord your God in the place named by him; at the feast of unleavened bread, the feast of weeks, and the feast of tents: and they are not to come before the Lord with nothing in their hands;