Charles H. Spurgeon on Psalms 40:7

Then said I. That is to say, when it was clearly seen that man's misery could not be remedied by sacrifices and offerings. It being certain that the mere images of atonement, and the bare symbols of propitiation were of no avail, the Lord Jesus, in propria persona, intervened. O blessed "then said I." Lord, ever give us to hear and feed on such living words as these, so peculiarly and personally thine own. Lo, I come. Behold, O heavens, and thou earth, and ye places under the earth! Here is something worthy of your most intense gaze. Sit ye down and watch with earnestness, for the invisible God comes in the likeness of sinful flesh, and as an infant the Infinite hangs at a virgin's breast! Immanuel did not send but come; he came in his own personality, in all that constituted his essential self he came forth from the ivory palaces to the abodes of misery; he came promptly at the destined hour; he came with sacred alacrity as one freely offering himself. In the volume of the book it is written of me. In the eternal decree it is thus recorded. The mystic roll of predestination which providence gradually unfolds, contained within it, to the Saviour's knowledge, a written covenant, that in the fulness of time the divine I should descend to earth to accomplish a purpose which hecatombs of bullocks and rams could not achieve. What a privilege to find our names written in the book of life, and what an honour, since the name of Jesus heads the page! Our Lord had respect to his ancient covenant engagements, and herein he teaches us to be scrupulously just in keeping our word; have we so promised, it is so written in the book of remembrance? then let us never be defaulters.