Charles H. Spurgeon on Psalms 51:14

Deliver me from bloodguiltiness. He had been the means of the death of Uriah, the Hittite, a faithful and attached follower, and he now confesses that fact. Besides, his sin of adultery was a capital offence, and he puts himself down as one worthy to die the death. Honest penitents do not fetch a compass and confess their sins in an elegant periphrasis, but they come to the point, call a spade a spade, and make a clean breast of all. What other course is rational in dealing with the Omniscient? O God, thou God of my salvation. He had not ventured to come so near before. It had been, O God, up till now, but here he cries, Thou God of my salvation. Faith grows by the exercise of prayer. He confesses sin more plainly in this verse than before, and yet he deals with God more confidently: growing upward and downward at the same time are perfectly consistent. None but the King can remit the death penalty, it is therefore a joy to faith that God is King, and that he is the author and finisher of our salvation. And my tongue shall sing aloud of thy righteousness. One would rather have expected him to say, I will sing of thy mercy; but David can see the divine way of justification, that righteousness of God which Paul afterwards spoke of by which the ungodly are justified, and he vows to sing, yea, and to sing lustily of that righteous way of mercy. After all, it is the righteousness of divine mercy which is its greatest wonder. Note how David would preach in the last verse, and now here he would sing. We can never do too much for the Lord to whom we owe more than all. If we could be preacher, precentor, doorkeeper, pew opener, foot washer, and all in one, all would be too little to show forth all our gratitude. A great sinner pardoned makes a great singer. Sin has a loud voice, and so should our thankfulness have. We shall not sing our own praises if we be saved, but our theme will be the Lord our righteousness, in whose merits we stand righteously accepted.