Exodus 12:40-42

40The Israelites had lived in Egypt for 430 years.

41It was on the last day of the 430 years that all the Lord's people left Egypt. They left in family groups, like an army.

42The Lord carefully watched his people all that night, when he brought them out of Egypt. Because of that, all Israelites must watch carefully during this special night. They and their descendants must do this every year, to thank the Lord.