Josh 18:15-19

15The southern side begins at the outskirts of Kiriath-jearim; and the boundary goes from there to Ephron, to the spring of the Waters of Nephtoah;16then the boundary goes down to the border of the mountain that overlooks the valley of the son of Hinnom, which is at the north end of the valley of Rephaim; and it then goes down the valley of Hinnom, south of the slope of the Jebusites, and downward to En-rogel;17then it bends in a northerly direction going on to En-shemesh, and from there goes to Geliloth, which is opposite the ascent of Adummim; then it goes down to the Stone of Bohan, Reuben's son;18and passing on to the north of the slope of Beth-arabah it goes down to the Arabah;19then the boundary passes on to the north of the slope of Beth-hoglah; and the boundary ends at the northern bay of the Dead Sea, at the south end of the Jordan: this is the southern border.