“Judah upon Jordan” is a disputed rendering of Joshua 19:34. The Authorized Version, following the Vulgate, uses this wording, while another reading makes Judah a separate reference and places the Jordan toward the east.
The phrase belongs to the description of tribal boundaries in Joshua.
The alternative interpretation follows the Masoretic punctuation. The supplied material also notes that the settlements called Havoth-jair east of Jordan were reckoned to Judah through Jair’s paternal connection.