Adam Clarke on Numbers 27:12

Get thee up into this Mount Abarim - The mountain which Moses was commanded to ascend was certainly Mount Nebo, see Deu 32:49, etc., which was the same as Pisgah, see Deu 34:1. The mountains of Abarim, according to Dr. Shaw, are a long ridge of frightful, rocky, precipitous hills, which are continued all along the eastern coast of the Dead Sea, as far as the eye can reach. As in Hebrew עבר abar signifies to pass over, Abarim here probably signifies passages; and the ridge in this place had its name in all likelihood from the passage of the Israelites, as it was opposite to these that they passed the Jordan into the promised land.