Exodus 25:17

17And thou shalt make a mercy-seat. The primary root of the verb כפר, caphar, from whence this noun is derived, (128) is used for “to smear with pitch,” but in the Hiphil conjugation, it signifies either to expiate, or to purge, or to receive into favor; whence כפר, copher, is expiation, as we have seen elsewhere; and כפרת, caphoreth, a covering or lid. Yet I doubt not but that Moses alludes in this word to a metaphorical meaning, for the law requires a covering to conceal our transgressions. And it is probable that, when Paul calls Christ ἱλαστήριον , (Romans 3:25,) and John ἱλασμὸν, (1 John 2:2,) they both refer to this figure, because God was propitiated towards believers by the covering of the Law, so as to shew Himself favorable to them by hearing their vows and prayers. For as long as the law stands forth before God’s face it subjects us to His wrath and curse; and hence it is necessary that the blotting out of our guilt should be interposed, so that God may be reconciled with us. Nor is it without reason that David exclaims, after he has proclaimed the righteousness of the law, “Who can understand his errors?” (Psalms 19:12.) Whence we gather that, without a propitiation, the law does not bring us near to God, but accuses us before Him. And assuredly, when I consider all things, it seems to me a tame explanation, that Moses spoke literally of the cover, when he (129) would have the Cherubim turn their faces toward it, and God promises that He will give His answers from it. By these honorable distinctions it is exalted above the Ark.