Charles Ellicott Commentary Leviticus 23:43

"that your generations may know that I made the children of Israel to dwell in booths, when I brought them out of the land of Egypt: I am Jehovah your God." — Leviticus 23:43 (ASV)

That your generations may know. —When their descendants are securely occupying the land of Canaan, the temporary dwelling in booths once a year may remind them of the goodness of God granted to their fathers in delivering them from the land of bondage, and sheltering them in booths in the wilderness.