Charles Ellicott Commentary Deuteronomy 2:29

"as the children of Esau that dwell in Seir, and the Moabites that dwell in Ar, did unto me; until I shall pass over the Jordan into the land which Jehovah our God giveth us." — Deuteronomy 2:29 (ASV)

Until I shall pass over Jordan. —This was already determined.