19 It then went to the northern slope of Beth Hoglah and came out at the northern bay of the Dead Sea, at the mouth of the Jordan in the south. This was the southern boundary.

Read Joshua 18:19 Using Other Translations

And the border passed along to the side of Bethhoglah northward: and the outgoings of the border were at the north bay of the salt sea at the south end of Jordan: this was the south coast.
Then the boundary passes on to the north of the shoulder of Beth-hoglah. And the boundary ends at the northern bay of the Salt Sea, at the south end of the Jordan: this is the southern border.
ran past the north slope of Beth-hoglah, and ended at the north bay of the Dead Sea, which is the southern end of the Jordan River. This was the southern boundary.