Psalms 51:15

Purge me with hyssop, with the blood of Christ applied to my soul by a lively faith, as the water of purification was sprinkled with a bunch of hyssop. The blood of Christ is called the blood of sprinkling, He 12:24. If this blood of Christ, which cleanses from all sin, cleanse us from our sin, then we shall be clean indeed, He 10:2. He asks not to be comforted, till he is first cleansed; if sin, the bitter root of sorrow, be taken away, he can pray in faith, Let me have a well-grounded peace, of thy creating, so that the bones broken by convictions may rejoice, may be comforted. Hide thy face from my sins; blot out all mine iniquities out of thy book; blot them out, as a cloud is blotted out and dispelled by the beams of the sun. And the believer desires renewal to holiness as much as the joy of salvation. David now saw, more than ever, what an unclean heart he had, and sadly laments it; but he sees it is not in his own power to amend it, and therefore begs God would create in him a clean heart. When the sinner feels this change is necessary, and reads the promise of God to that purpose, he begins to ask it. He knew he had by his sin grieved the Holy Spirit, and provoked him to withdraw. This he dreads more than anything. He prays that Divine comforts may be restored to him. When we give ourselves cause to doubt our interest in salvation, how can we expect the joy of it? This had made him weak; he prays, I am ready to fall, either into sin or into despair, therefore uphold me with thy Spirit. Thy Spirit is a free Spirit, a free Agent himself, working freely. And the more cheerful we are in our duty, the more constant we shall be to it. What is this but the liberty wherewith Christ makes his people free, which is contrasted with the yoke of bondage? Ga 5:1. It is the Spirit of adoption spoken to the heart. Those to whom God is the God of salvation, he will deliver from guilt; for the salvation he is the God of, is salvation from sin. We may therefore plead with him, Lord, thou art the God of my salvation, therefore deliver me from the dominion of sin. And when the lips are opened, what should they speak but the praises of God for his forgiving mercy?

O Lord, open thou my lips. He is so afraid of himself that he commits his whole being to the divine care, and fears to speak till the Lord unstops his shame silenced mouth. How marvellously the Lord can open our lips, and what divine things can we poor simpletons pour forth under his inspiration! This prayer of a penitent is a golden petition for a preacher, Lord, I offer it for myself and my brethren. But it may stand in good stead any one whose shame for sin makes him stammer in his prayers, and when it is fully answered, the tongue of the dumb begins to sing. And my mouth shall shew forth thy praise. If God opens the mouth he is sure to have the fruit of it. According to the porter at the gate is the nature of that which comes out of a man's lips; when vanity, anger, falsehood, or lust unbar the door, the foulest villainies troop out; but if the Holy Spirit opens the wicket, then grace, mercy, peace, and all the graces come forth in tuneful dances, like the daughters of Israel when they met David returning with the Philistine's head.