Akrabbim
Akrabbim — "the ascent of Akrabbim" in every UPDV occurrence — names a pass on the southern boundary of the land, between Edomite and Israelite territory.
The Southern Border
When Yahweh marks out the limits of the inheritance for Moses, the southern line bends past Akrabbim: "and your⁺ border will turn about southward of the ascent of Akrabbim, and pass along to Zin; and the goings out of it will be southward of Kadesh-barnea; and it will go forth to Hazar-addar, and pass along to Azmon" (Nu 34:4). The pass is one of the named bends in the boundary line.
The same line is traced again in the allotment of Judah, with almost the same waypoints: "and it went out southward of the ascent of Akrabbim, and passed along to Zin, and went up by the south of Kadesh-barnea, and passed along by Hezron, and went up to Addar, and turned about to Karka" (Jos 15:3). What was prescribed in Numbers as Israel's border is here applied as Judah's southern boundary.
The Edge between Amorite and Edomite
Judges places Akrabbim at the line between Amorite and Edomite territory: "And the border of the Amorites was the Edomites, from the ascent of Akrabbim, from the rock, and upward" (Judges 1:36). The same pass that defined the limits of inheritance in Numbers and Joshua marks the limits of Amorite reach here.