Albert Barnes Commentary Judges 1:36

"And the border of the Amorites was from the ascent of Akrabbim, from the rock, and upward." — Judges 1:36 (ASV)

The going up to Akrabbim - See the margin and references; properly “the ascent of scorpions,” with which the whole region abounds.

The rock - Petra, the capital of Idumea, so called from the mass of precipitous rock which encloses the town, and out of which many of its buildings are excavated. The original word “Selah” is always used of the rock at Kadesh-Barnea (Numbers 20:8–11), near Petra . This leads us to look for “the ascent of scorpions,” here coupled with הַסֶּלַע (has-sela‘), in the same neighborhood.