7. Thou shalt purge me with hyssop. He still follows out the same strain of supplication; and the repetition of his requests for pardon proves how earnestly he desired it. He speaks of hyssop¹, in allusion to the ceremonies of the law; and though he was far from putting his trust in the mere outward symbol of purification, he knew that, like every other legal rite, it was instituted for an important end. The sacrifices were seals of the grace of God. In them, therefore, he was anxious to find assurance of his reconciliation; and it is highly proper that, when our faith is disposed at any time to waver, we should confirm it by improving such means of divine support. All which David here prays for is, that God would effectually accomplish, in his experience, what he had signified to his Church and people by these outward rites; and in this he has set us a good example for our imitation. It is no doubt to the blood of Christ alone that we must look for the atonement of our sins; but we are creatures of sense, who must see with our eyes, and handle with our hands; and it is only by improving the outward symbols of propitiation that we can arrive at a full and assured persuasion of it. What we have said of the hyssop applies also to the washings² referred to in this verse, and which were commonly practiced under the Law. They figuratively represented our being purged from all iniquity, in order to our reception into the divine favor. I need not say that it is the peculiar work of the Holy Spirit to sprinkle our consciences inwardly with the blood of Christ, and, by removing the sense of guilt, to secure our access into the presence of God.

In the two verses which follow, the Psalmist prays that God would be pacified towards him. Those put too confined a meaning upon the words who have suggested that, in praying to hear the voice of joy and gladness, he requests some prophet to be sent, who might assure him of pardon. He prays, in general, for testimonies of the divine favor. When he speaks of his bones as having been broken, he alludes to the extreme grief and overwhelming distress to which he had been reduced. The joy of the Lord would reanimate his soul; and this joy he describes as to be obtained by hearing; for it is the word of God alone which can first and effectually cheer the heart of any sinner. There is no true or solid peace to be enjoyed in the world except in the way of reposing upon the promises of God. Those who do not resort to them may succeed for a time in hushing or evading the terrors of conscience, but they must ever be strangers to true inward comfort. And, granting that they may attain to the peace of insensibility, this is not a state which could satisfy any man who has seriously felt the fear of the Lord. The joy which he desires is that which flows from hearing the word of God, in which he promises to pardon our guilt, and readmit us into his favor. It is this alone which supports the believer amidst all the fears, dangers, and distresses of his earthly pilgrimage; for the joy of the Spirit is inseparable from faith. When God is said, in the 9th verse, to hide his face from our sins, this signifies his pardoning them, as is explained in the clause immediately annexed -- Blot out all my sins. This represents our justification as consisting in a voluntary act of God, by which he condescends to forget all our iniquities; and it represents our cleansing to consist in the reception of a gratuitous pardon. We repeat the remark which has been already made, that David, in thus reiterating his one request for the mercy of God, evinces the depth of that anxiety which he felt for a favor which his conduct had rendered difficult of attainment. The man who prays for pardon in a mere formal manner, is proved to be a stranger to the dreadful desert of sin. "Happy is the man," said Solomon, "that feareth alway," (Proverbs 28:14.)

But here it may be asked why David needed to pray so earnestly for the joy of remission, when he had already received assurance from the lips of Nathan that his sin was pardoned? (2 Samuel 12:13.) Why did he not embrace this absolution? and was he not chargeable with dishonoring God by disbelieving the word of his prophet? We cannot expect that God will send us angels in order to announce the pardon which we require. Was it not said by Christ, that whatever his disciples remitted on earth would be remitted in heaven? (John 20:23.) And does not the apostle declare that ministers of the gospel are ambassadors to reconcile men to God? (2 Corinthians 5:20.) From this it might appear to have argued unbelief in David, that, notwithstanding the announcement of Nathan, he should evince a remaining perplexity or uncertainty regarding his forgiveness. There is a twofold explanation which may be given of the difficulty. We may hold that Nathan did not immediately make him aware of the fact that God was willing to be reconciled to him. In Scripture, it is well known, things are not always stated according to the strict order of time in which they occurred. It is quite conceivable that, having thrown him into this situation of distress, God might keep him in it for a considerable interval, for his deeper humiliation; and that David expresses in these verses the dreadful anguish which he endured when challenged with his crime, and not yet informed of the divine determination to pardon it. Let us take the other supposition, however, and it by no means follows that a person may not be assured of the favor of God, and yet show great earnestness and importunity in praying for pardon. David might be much relieved by the announcement of the prophet, and yet be visited occasionally with fresh convictions, influencing him to have recourse to the throne of grace. However rich and liberal the offers of mercy may be which God extends to us, it is highly proper on our part that we should reflect upon the grievous dishonor which we have done to his name, and be filled with due sorrow on account of it. Then our faith is weak, and we cannot at once apprehend the full extent of the divine mercy; so that there is no reason to be surprised that David should have once and again renewed his prayers for pardon, the more to confirm his belief in it. The truth is, that we cannot properly pray for the pardon of sin until we have come to a persuasion that God will be reconciled to us. Who can venture to open his mouth in God's presence unless he be assured of his fatherly favor? And pardon being the first thing we should pray for, it is plain that there is no inconsistency in having a persuasion of the grace of God, and yet proceeding to supplicate his forgiveness. In proof of this, I might refer to the Lord's Prayer, in which we are taught to begin by addressing God as our Father, and yet afterwards to pray for the remission of our sins. God's pardon is full and complete; but our faith cannot take in his overflowing goodness, and it is necessary that it should distil to us drop by drop. It is owing to this infirmity of our faith, that we are often found repeating and repeating again the same petition, not with the view surely of gradually softening the heart of God to compassion, but because we advance by slow and difficult steps to the requisite fullness of assurance. The mention which is here made of purging with hyssop, and of washing or sprinkling, teaches us, in all our prayers for the pardon of sin, to have our thoughts directed to the great sacrifice by which Christ has reconciled us to God. "Without shedding of blood," says Paul, "is no remissions" (Hebrews 9:22 ;) and this, which was intimated by God to the ancient Church under figures, has been fully made known by the coming of Christ. The sinner, if he would find mercy, must look to the sacrifice of Christ, which expiated the sins of the world, glancing, at the same time, for the confirmation of his faith, to Baptism and the Lord's Supper; for it were vain to imagine that God, the Judge of the world, would receive us again into his favor in any other way than through a satisfaction made to his justice.