It will come to pass when you come to the land which the LORD will give you, just as He promised, that you shall keep this service.
Exodus 12:25
Surrounding context
12:24 And you shall observe this thing as an ordinance for you and your sons forever.
12:25 It will come to pass when you come to the land which the LORD will give you, just as He promised, that you shall keep this service.
12:26 And it shall be, when your children say to you, "What do you mean by this service?'