'Wadi' in the Bible

"You are to determine the southern extremity running from Tamar as far as the waters of Meribath-kadesh, then from there proceeding to the Wadi, and then to the Mediterranean Sea. This is to be the southern perimeter.

Adjacent to the border of Gad to the south and extending toward the south, the border is to proceed from Tamar to the waters of Meribath-kadesh, then to the Wadi of Egypt, and from there to the Mediterranean Sea.