Charles Ellicott Commentary Joshua 15:10

"and the border turned about from Baalah westward unto mount Seir, and passed along unto the side of mount Jearim on the north (the same is Chesalon), and went down to Beth-shemesh, and passed along by Timnah;" — Joshua 15:10 (ASV)

Mount Seir. —Of course, entirely distinct from the place in Edom, but not precisely identified.

Chesalon is identified with Kesla, two and a quarter miles due north of Khurbet ’Erma, on sheet 17. Timnah is Tibneh (on sheet 16).