Albert Barnes Commentary Psalms 45:16

"Instead of thy fathers shall be thy children, Whom thou shalt make princes in all the earth." — Psalms 45:16 (ASV)

Instead of thy fathers shall be thy children - Instead of your fame, your celebrity, your distinction, being derived from your illustrious predecessors, it will in the future be derived rather from your sons, from the fact that they will be made princes and rulers in the earth. In our translation, this would seem to be an address to the bridal-queen, as if to console her for leaving the home of her illustrious ancestors by the assurance that she would have children of her own who would be still more illustrious. The connection, however, and the original—at least, in the Masoretic pointing—demand that this should be understood as an address to the king himself—the main subject in the poem, as in Psalm 45:2-9. The idea is that he would ultimately derive his dignity and honor not so much from his ancestors as from his descendants. Those born to him would be more illustrious and have a wider dominion than any who had gone before him in the line of his descent.

It is not easy or practicable to apply this to Solomon or to any other Hebrew prince. It is not difficult, however, to apply it to the Messiah, and to the fact that those who would be spiritually descended from him—and who would ultimately be regarded as deriving true rank and honor from him—would far surpass in dignity all those who, in the line of kings, had been his predecessors.

Whom thou mayest make princes in all the earth - not merely assigning them provinces to be governed as part of the empire, but [their being princes] in all lands, or where your dominion will be acknowledged all over the world. The image here is derived, undoubtedly, from the custom prevailing among kings of assigning portions of an empire as provinces to their sons. The meaning, however, considered as referring to the Messiah, is that his luster and dignity on earth would not be derived from a distinguished earthly ancestry or from an illustrious line of kings from whom he descended. Instead, it would come from the fact that those who derive their authority from him would ultimately possess the world, and that this authority under him would extend to all lands. Compare the notes at Daniel 7:14 and the notes at Daniel 7:27.