Numbers 24:18 - Joseph Benson’s Commentary on the Old and New Testaments

Edom shall be a possession “This was also fulfilled by David; for throughout all Edom put he garrisons, and all they of Edom became David's servants, 2 Samuel 8:14. David himself, in two of his Psalms, (Psalms 60:8; and Psalms 108:9;) hath mentioned together his conquest of Moab and Edom, as they are also joined together in this prophecy.” Seir is the name of the mountains of Edom, which were also possessed by David. Israel shall do valiantly As they did, particularly under the command of David.