Restore unto me the joy of thy salvation; and uphold me [with thy] free spirit.
Ver. 12. Restore unto me the joy of thy salvation] He had grieved that holy thing, that Spirit of God whereby he was sealed to the day of redemption, Ephesians 4:30, and is therefore at a loss for comfort; he had vilipended that patent of his pardon which God had passed under his hand and seal; God therefore calleth for it home again into the pardon office, as it were, that he may know the worth by the want. A man may sin away, not only the sense and comfort of his pardon, but the evidence and knowledge of it, as that place of Peter seemeth to imply, 2 Peter 1:9. Mountebanks, who wound their flesh to try conclusions upon their own bodies how sovereign the salve is, do oft feel the smart of their presumption, by long and desperate wounds: so God will let his Davids see what it is to make wounds in their consciences to try the preciousness of his balsam; such may go mourning to their graves (Dr Sibbes' Soul's Confl.). And though with much ado they get assurance of pardon, yet their consciences will be still trembling, till God at length speak further peace; even as the waters of the sea after a storm are not presently still, but move and tremble a good while after the storm is over.
And uphold me with thy free spirit] Heb. Firmly sustain me with thy noble or princely Spirit, that may make me steady and ready to come off roundly in thy service. Sin against conscience disableth for duty, taketh away freedom to it and stability in it. David, therefore, prays God to fix his quicksilver, to balance his lightness, to settle and fill that vain and empty heart of his with something that may stay and stablish it, that may also free and enlarge it (for where the Spirit of God is there is liberty, 2Co 3:17), that he might yield prompt and present obedience to God in all things; and withal might be apt and able to teach transgressors, as he promiseth to do in the next words.