A God prepares Israel to leave Egypt, he gives the command to celebrate the Passover as a lasting ordinance. Then he adds an interesting coda
12:24 “Obey these instructions as a lasting ordinance for you and your descendants. 25 When you enter the land that the Lord will give you as he promised, observe this ceremony. 26 And when your children ask you, ‘What does this ceremony mean to you? ‘ 27 then tell them, ‘It is the Passover sacrifice to the Lord, who passed over the houses of the Israelites in Egypt and spared our homes when he struck down the Egyptians. ‘”
The ritual of Passover was a ritual of remembrance. A thing was done to remind Israel of the past, and it was intended for children to ask “why are we doing this” and for the adults to give an answer.
13:8 On that day tell your son, ‘I do this because of what the Lord did for me when I came out of Egypt. ‘ 9 This observance will be for you like a sign on your hand and a reminder on your forehead that this law of the Lord is to be on your lips. For the Lord brought you out of Egypt with his mighty hand. 10 You must keep this ordinance at the appointed time year after year.
14 “In days to come, when your son asks you, ‘What does this mean? ‘ say to him, ‘With a mighty hand the Lord brought us out of Egypt, out of the land of slavery. 15 When Pharaoh stubbornly refused to let us go, the Lord killed the firstborn of both people and animals in Egypt. This is why I sacrifice to the Lord the first male offspring of every womb and redeem each of my firstborn sons. ‘ 16 And it will be like a sign on your hand and a symbol on your forehead that the Lord brought us out of Egypt with his mighty hand.”