Charles Ellicott Commentary Deuteronomy 4:5

"Behold, I have taught you statutes and ordinances, even as Jehovah my God commanded me, that ye should do so in the midst of the land whither ye go in to possess it." — Deuteronomy 4:5 (ASV)

That you should do so in the land. —It should never be forgotten that there is a special connection between the law of Moses and the land of Canaan. It cannot be kept in many of its precepts, except by a chosen people in a protected land.