Exodus 12:37-42

37Then Bnei-Yisrael journeyed from Rameses to Succoth, about 600,000 men on foot, as well as children.

38Also a mixed multitude went up with them, along with the flocks, herds and heavy livestock.

39They had baked matzot cakes from the dough that they brought out of Egypt. It had no hametz, because they were thrust out of Egypt and could not delay, so they had not made provisions for themselves.

40Now the time that Bnei-Yisrael lived in Egypt was 430 years.

41So it happened at the end of 430 years, to the very day, that all the armies of Adonai went out from the land of Egypt.

42It was a night of watching for Adonai to bring them out of the land of Egypt. This same night is a night of vigil for Adonai, for all Bnei-Yisrael throughout their generations.