Adam Clarke on Psalms 45:16

Instead of thy fathers shalt be thy children - This is the third part, or prophetic declaration relative to the numerous and powerful issue of this marriage. Instead of the kindred, which thou hast left behind in Egypt, thou shalt have numerous children. This cannot refer either to Solomon, or to the daughter of Pharaoh; for there is no evidence that he ever had a child by Pharaoh's daughter; and it is very certain that Rehoboam, Solomon's successor, was not son to the daughter of Pharaoh; nor did any princes of that line ever occupy a foreign throne; nor by successive generations ever continue the remembrance of Solomon and his Egyptian queen. The children mentioned here are generally supposed to mean the apostles and their successors in the Christian ministry; founding Churches all over the world, by whom the Christian name becomes a memorial through all the earth.