God insists that the Israelites who received Deuteronomy are to be thought of as the Exodus generation.
There are two ways to read this passage. The first interpretation sees that God is speaking to a narrow age-range of Israelites who were children in Egypt (less than 20 years old) who have grown up, but not yet died in the wilderness. These children were old enough to see and understand God’s miracles in Egypt, but were young enough to be held innocent in the episode of the spies in Numbers 13 & 14 (see, especially Numbers 14:28-32).
Alternatively, and this has been a dominant interpretation in most Jewish circles, is the understanding that God regards every generation who encounters this text as the Exodus generation. That is, not for ancestors and not for descendants, but for this generation – in every generation – did God work freedom and liberation from the house of bondage. This ongoing A covenant is a promise or agreement. In the Bible the promises made between God and God's people are known as covenants; they state or imply a relationship of commitment and obedience. More did not take place for one generation only, but for every generation. And each generation is to regard itself as if they had seen the signs and wonders God performed in Exodus personally. They are to place themselves in the story.
Perhaps there is an invitation to Christian readers as well, not to supersede or appropriate the Exodus story, but to picture themselves as members of the mixed-multitude (Exodus 12:38) that accompanied the Israelites into the wilderness after seeing the signs of God.