My mercy will I keep for him for evermore
That is, for his mystical body, his church and people; for whom stores of mercy are kept with him, to be laid out in their regeneration, pardon, salvation, and eternal life; for to them the mercy of God is from everlasting to everlasting, ( Psalms 103:17 ) , unless this is to be understood of the "grace" and "kindness" F7 of God, as the word may be rendered; his free favour and love to Christ, which always continues; for as he was always his dearly beloved Son, that lay in his bosom from eternity, so he continued, throughout his state, of humiliation, his well beloved, in whom he was well pleased, and still is, and ever will:
and my covenant shall stand fast with him;
being made with him as the head and representative of his people, it remains, and will remain, sure, firm, and immoveable; its blessings are "sure mercies", and its promises are all "yea and amen in Christ": the stability of it, and of all that is in it, is owing to its being made with him, and being in his hands, who is the surety, Mediator, and messenger of it.