And I the Lord will be their God,.... The God of them Christ is the shepherd of, and whom he feeds; the sheep and poor of the flock: this is the great blessing of the everlasting covenant, and than which there cannot be a greater, to have the Lord, the everlasting and unchangeable Jehovah, to be a covenant God and Father:
and my servant David a Prince among them; who should reside among them, dwell with them, by granting them his spiritual presence, and so rule over them, protect and defend them; even he who is the Prince of the kings of the earth, and is exalted, a Prince and a Saviour of his people Israel; he is such a Shepherd as that he is a Prince; and such a Prince as that he is a Saviour and under whose princely government is the greatest safety:
I the Lord have spoken it; and therefore it shall assuredly be. The Targum is,
"I the Lord have decreed it in my word;''
he had determined it within himself, and promised it in covenant, and spoke of it in prophecy, and it should be fulfilled.