Joshua 15:2-4

2And their south border was from the uttermost part of the Salt Sea, from the bay that looked southward:

3and it went out southward of the ascent of Akrabbim, and passed along to Zin, and went up by the south of Kadesh-barnea, and passed along by Hezron, and went up to Addar, and turned about to Karka:

4and it passed along to Azmon, and went out at the brook of Egypt; and the goings out of the border were at the sea: this shall be your south border.