Boyd’s Bible Dictionary:
(waste). Perhaps desert or plain (Num. 21:20; 23:28).
Concise Bible Dictionary:
Plain or desert seen from the tops of Pisgah and Peor (Num. 21:20; Num. 23:28). Perhaps the same as that mentioned in 1 Samuel 23:19, 24 and 1 Samuel 26:1, 3. It was in the south, on the west of the Dead Sea. Some do not treat Jeshimon as a proper name, but translate it “the waste” in all places.
Jackson’s Dictionary of Scripture Proper Names:
the wilderness