Leviticus 14:2

2This shall be the law of the leper. Moses now treats of the manner in which those who were cured of leprosy were to be cleansed and restored. Thus far he had shewn whom the priest was to admit into the holy congregation, and account to be clean; he now prescribes the rite of expiation, whereby the people might learn how greatly God abominates the uncleanness, which He commands to be purified by a solemn propitiation; and also that he who is healed may acknowledge that he is rescued from death by God’s special blessing, and may in future be more diligent in seeking to be pure. For there were two parts in the sacrifice here demanded-purification and thanksgiving. But we must ever keep in view the object which I have stated in the last chapter, that the Israelites were instructed by this ceremony to serve God in chastity and purity, and to keep far away from those defilements, whereby religion would be profaned. Since, then, leprosy was a kind of pollution, God was unwilling that those who were cured of it should be received into the holy congregation, (13) except after the offering of a sacrifice; as if the priest reconciled them after excommunication. It will now be well to discuss the points which are worthy of consideration. The office of cleansing is imposed on the priest; yet he is at the same time forbidden to cleanse any except those who were already pure and clean. In this, on the one hand, God claims for Himself the honor of the cure, lest men should assume it; and also establishes the discipline which He would have to reign in His Church. To make the matter clearer, it belongs to God only to forgive sins; what, then, remains to man, except to be the witness and herald of the grace which He confers? God’s minister can, therefore, absolve none whom God has not before absolved. In sum, absolution is not in the power or will of man: the minister only sustains an inferior part, to endorse God’s judgment, or rather to proclaim God’s sentence. Hence that remarkable expression of Isaiah, “I, even I, am he that blotteth out thy transgressions, O Israel, and none but me. ” (14) (Isaiah 43:25.) In which sense, too, God everywhere promises by the prophets that the people shall be clean, when He shall have cleansed them. Meanwhile, however, this does not prevent those who are called to the office of teaching from purging the uncleanness of the people in a certain peculiar way. For, since faith alone purifies the heart, in so far as it receives the testimony which God proffers by the mouth of man, the minister who testifies that we are reconciled to God, is justly reckoned to take away our pollution. This expiation is still in force, though the ceremony has long ceased to be in use. But, since the spiritual healing, which we receive by faith, proceeds from the mere grace of God, the ministry of man does not at all detract from His glory. Let us, then, remember that these two things are perfectly consistent with each other, that God is the sole author of our purity; and yet that the method, which He uses for our justification, must not on that account be neglected. And this is properly referred to discipline, that whosoever has been once cast out of the holy congregation by public authority, must not be received again except upon professing penitence and a new life. We must observe, too, that this jurisdiction was given to the priests not only on the ground that they represented Christ, but also in respect to the ministry, which we have in common with them.