Numbers 21:21-24

Then Israel sent messengers to Sihon, king of the Amorites, saying, “Let me pass through your land; we will not turn away [from the road] into field or vineyard; we will not drink the water of the wells. We will go by the king’s highway until we have crossed your border.” But Sihon would not allow Israel to pass through his border. Instead Sihon gathered all his people together and went out against Israel into the wilderness, and came to Jahaz, and he fought against Israel. Then Israel struck the king of the Amorites with the edge of the sword and took possession of his land from the Arnon to the Jabbok, as far as the Ammonites, for the boundary of the Ammonites was strong.