Judges 11:16, 18

but when they came up from Egypt, and Israel went through the wilderness unto the Red Sea, and came to Kadesh

Then they went through the wilderness, and went around the land of Edom, and the land of Moab, and came by the east side of the land of Moab, and they encamped on the other side of the Arnon; but they came not within the border of Moab, for the Arnon was the border of Moab.