Exodus 12:29, 33, 42, 51

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

And the Egyptians urged the people, that they might send them out of the land in haste. For they said, “We shall all be dead.”

It is a night of solemn observance to the LORD for bringing them out of the land of Egypt. This is that night of the LORD, a solemn observance for all the children of Israel throughout their generations.

And it came to pass, on that very same day, that the LORD brought the children of Israel out of the land of Egypt according to their armies.