Numbers 21:22-23

22Let us pass through thy land; we will not turn into the fields, or into the vineyards; we will not drink water out of the wells; on the king's road will we go until we have passed thy border.

23But Sihon would not suffer Israel to go through his border; and Sihon gathered all his people, and went out against Israel into the wilderness, and came to Jahaz, and fought against Israel.