For I have said,.... That is, in his heart he had said, he had thought of it, was assured of it, strongly concluded it, from the Spirit and word of God; he believed it, and therefore he spoke it; having it from the Lord, it was all one as if he had spoke it: For I have said,.... That is, in his heart he had said, he had thought of it, was assured of it, strongly concluded it, from the Spirit and word of God; he believed it, and therefore he spoke it; having it from the Lord, it was all one as if he had spoke it: Psalms 89:3 psa 89:3 psa 89:3 psa 89:3I have made a covenant with my chosen,.... Not with Abraham, as the Targum expresses it: but with David, as in the following clause; not David, literally understood, though he was chosen of the Lord to be his servant, and a covenant was made with him, and a promise made to him of the perpetuity of his throne and kingdom in his family, Psa 78:70 but mystical David, the Messiah, David's son and antitype; after, on this account, called David in Scripture, Eze 34:23 and who is the Lord's "chosen" One, foreordained to be the Redeemer of lost sinners, chosen to be the Mediator between God and them, to be the head of the church, and Saviour of the body; and his human nature was chosen to the grace of union to the Son of God, Psa 89:19, hence he is called God's elect, Isa 43:1 and with him the covenant of grace was made from all eternity, and all the blessings and promises of it were put into his hands; he is the Mediator, surety, and messenger of it, and by his blood it is ratified and confirmed: the Septuagint render it, in the plural number, "with mine elect ones"; and it is a truth, that the covenant of grace is made with all the elect, considered in Christ, and is made with them as such, and not as believers, converted persons, &c. election is the foundation of the covenant, and the source of all covenant blessings: I have sworn unto David my servant: to the Messiah, called David, as before observed, and who is the Lord's servant, as man and Mediator, of his choosing, calling, sending, and supporting, Isa 42:1, to whom he swore, and he will not repent; and which oath of his, joined to his covenant and promise, makes for the strong consolation of the heirs of promise; see Psa 89:35, the sum and substance of which covenant and oath follow.