Deuteronomy 2:16-19

So when death had overtaken all the men of war among the people, The word of the Lord came to me, saying, You are about to go by Ar, the limit of the country of Moab; And when you come near the land of the children of Ammon, give them no cause of trouble and do not make war on them, for I will not give you any of the land of the children of Ammon for your heritage: because I have given it to the children of Lot.