Joshua 15:1-5

Now the lot for the tribe of the sons of Judah according to their families reached the border of Edom, southward to the wilderness of Zin at the extreme south.

Their southern border was from the lower end of the Salt Sea, from the bay that turns to the south.

Then it proceeded southward to the ascent of Akrabbim and continued to Zin, then went up by the south of Kadesh-barnea and continued to Hezron, and went up to Addar and turned to Karka.

It continued to Azmon and proceeded to the brook of Egypt, and the border ended at the sea. This shall be your southern border.

The eastern border was the Salt Sea, as far as the mouth of the Jordan. And the border of the north side was from the bay of the sea at the mouth of the Jordan.