Charles Ellicott Commentary Deuteronomy 2:9

"And Jehovah said unto me, Vex not Moab, neither contend with them in battle; for I will not give thee of his land for a possession; because I have given Ar unto the children of Lot for a possession." — Deuteronomy 2:9 (ASV)

Distress not the Moabites ... I have given Ar unto the children of Lot. —The children of Lot, like those of Ishmael and Esau, had their earthly inheritance before the children of Abraham.