Cross reference
Exodus 12:42
42 It is a watch-night before the Lord who took them out of the land of Egypt: this same night is a watch-night to the Lord for all the children of Israel, through all their generations.
Deuteronomy 16:1-6
1 Take note of the month of Abib and keep the Passover to the Lord your God: for in the month of Abib the Lord your God took you out of Egypt by night.
2 The Passover offering, from your flock or your herd, is to be given to the Lord your God in the place marked out by him as the resting-place of his name.
3 Take no leavened bread with it; for seven days let your food be unleavened bread, that is, the bread of sorrow; for you came out of the land of Egypt quickly: so the memory of that day, when you came out of the land of Egypt, will be with you all your life.
4 For seven days let no leaven be used through all your land; and nothing of the flesh which is put to death in the evening of the first day is to be kept through the night till morning.
5 The Passover offering is not to be put to death in any of the towns which the Lord your God gives you:
6 But in the place marked out by the Lord your God as the resting-place of his name, there you are to put the Passover to death in the evening, at sundown, at that time of the year when you came out of Egypt.
Exodus 12:14
14 And this day is to be kept in your memories: you are to keep it as a feast to the Lord through all your generations, as an order for ever.
Exodus 13:10
10 So let this order be kept, at the right time, from year to year.