Charles Ellicott Commentary Deuteronomy 12:8

"Ye shall not do after all the things that we do here this day, every man whatsoever is right in his own eyes;" — Deuteronomy 12:8 (ASV)

You shall not do after all the things that we do here this day. —Another precept strongly marked with the condition of Israel in the wilderness. It has been too much overlooked by recent commentators that the law of Moses has a prophetic side. It was given to him and to Israel at a time when they were not in a position to keep it. It was the law of the land which God would give them. In many ways its observance depended on the completion of the conquest of the land, and upon the quietness of the times in which they lived. This prophetic aspect was certainly not unrecognized by the Jews, or they would not (for example) have neglected to dwell in booths at the Feast of Tabernacles from the time of Joshua to Nehemiah .

And compare the curious position of the Law in Leviticus which required them to dwell in booths. It occurs as an appendix outside the regular laws of that festival (Leviticus 23:37–43).