Exodus 12:29, 33, 42, 51

And it came to pass, that at midnight the LORD smote all the firstborn in the land of Egypt, from the firstborn of Pharaoh that sat on his throne unto the firstborn of the captive that was in the dungeon; and all the firstborn of cattle.

And the Egyptians were urgent upon the people, that they might send them out of the land in haste; for they said, We be all dead men.

It is a night to be much observed unto the LORD for bringing them out from the land of Egypt: this is that night of the LORD to be observed of all the children of Israel in their generations.

And it came to pass the selfsame day, that the LORD did bring the children of Israel out of the land of Egypt by their armies.