Thou art to pass over through Ar,.... That is, over the river Arnon, by the city Ar of Moab, which was situated by it; see Deu 2:9 and so Moses and the people of Israel were to pass along by that: and by the coast of Moab; for they were not admitted to enter the land and pass through it; only to travel on the borders of it, and that they were to begin to do this day; the day the Lord spake to Moses.