Exodus 12:40

38A mixed multitude went up also with them, with flocks, herds, and even very much livestock.

39They baked unleavened cakes of the dough which they brought out of Egypt; for it wasn’t leavened, because they were thrust out of Egypt, and couldn’t wait, and they had not prepared any food for themselves.

40Now the time that the children of Israel lived in Egypt was four hundred thirty years.

41At the end of four hundred thirty years, to the day, all of the LORD’s armies went out from the land of Egypt.

42It is a night to be much observed to the LORD for bringing them out from the land of Egypt. This is that night of the LORD, to be much observed by all the children of Israel throughout their generations.