And the boundary goes up to Debir from the Valley of Achor, and so northward, turning toward Gilgal, which is opposite the ascent of Adummim, which is on the south side of the valley. And the boundary passes along to the waters of En-shemesh and ends at En-rogel.
Judah and Joseph were the two sons of Jacob on whom Reuben's forfeited birth-right devolved. Judah had the dominion entailed on him, and Joseph the double portion, and therefore these two tribes were first seated, Judah in the southern part of the land of Canaan and Joseph in the northern part, and on them the other seven did attend, and had their respective lots as...
Commenting on Joshua 15:1-12
And the border went up towards Debir,.... This was neither the Debir in the tribe of Gad, on the other side Jordan, Jos 13:26; nor that in the tribe of Judah near Hebron, Jos 15:15; but a third city of that name, and was not far from Jericho: from the valley of Achor; where Achan was put to death, and had its name from thence...
Achor--(see on Jos 7:26). Adummim--a rising ground in the wilderness of Jericho, on the south of the little brook that flowed near Jericho (Jos 16:1). En-shemesh--"the fountain of the sun"; "either the present well of the apostle, below Bethany, on the road to Jericho, or the fountain near to St. Saba" [ROBINSON].