Leviticus 23:4-8

Passover and bread without yeast

4 There are other special days. They are holy feasts. On these days you must tell the people how to obey the Lord's rules. 5 One special day is the 14th day of the first month. When the sun goes down, the Passover to the Lord begins. 6 The 15th day of the first month, the Feast of Flat Bread begins. It is a feast to the Lord. For seven days the people must eat bread that has no yeast in it. 7 On the first day the people must meet together and they must not work. 8 For seven days the people must give burnt offerings to the Lord. On the seventh day they must stop work and they must worship the Lord.’

23:8The Lord caused Israel's people to stay in their houses for their last night in Egypt. They had to put a mark on their doors with blood. The Lord's servant who was a spirit killed the oldest son in each house of Egypt's people. But he passed over the houses with blood round the doors. So the Lord saved the sons of the Israelites. That is why this is called the Passover feast. (See Exodus 12:12-20.)