Matthew Poole and continuators on Joshua 15:8

8 And the border went up by the valley of the son of Hinnom , unto the south-side of the * Jebusite , the same is Jerusalem : and the border went up to the top of the mountain, that lieth before the valley of Hinnom, westward, which is at the end of the valley of the giants, northward.

Properly, for the Line went from Iordan and the salt-Sea, to the higher grounds nigh Ierusalem; and therefore the Line is said to go down, Josh. 18. 16. because there it takes a contrary course, and goes downwards to Iordan and the Sea.

A very pleasant place, but afterward made infamous, 2 King. 23. 10

i. e. Of the City of the Iebusites, which was anciently called Iebusi, Josh. 18. last, Iudg. 19. 10.

It may seem hence, and from Deut. 33. 12. Iosh. 18. last. Iudg. 1. 21. that Ierusalem properly, or at least principally, belonged to Benjamin; and yet it is ascribed to Iudah also here, v. 63. and elsewhere, either because a part of the City was allotted to Iudah; or because the Benjamites needed or desired the help and conjunction of this powerful Tribe of Iudah for the getting and keeping of this most important place. And when the Benjamites had in vain attempted to drive out the Iebusites, this work was at last done by the Tribe of Iudah, who therefore had an interest in it by the right of war; as Ziglag which belonged to the Tribe of Simeon, being gotten from the Philistines by David, was adjoined by him to his Tribe of Iudah, 1 Sam. 27. 6.