I shall see him - rather, “I do see” or “I have seen him” - a prophetic sight, like that of Abraham (Joh 8:56).
him - that is, Israel.
there shall come a Star out of Jacob, and a Sceptre shall rise out of Israel - This imagery, in the hieroglyphic language of the East, denotes some eminent ruler - primarily David; but secondarily and pre-eminently, the Messiah (see on Gen 49:10).
corners - border, often used for a whole country (Exo 8:2; Psa 74:17).
children of Sheth - some prince of Moab; or, according to some, “the children of the East.”