Ps 51:1-19. On the occasion, compare 2Sa 11:12. The Psalm illustrates true repentance, in which are comprised conviction, confession, sorrow, prayer for mercy, and purposes of amendment, and it is accompanied by a lively faith.
1-4. A plea for mercy is a confession of guilt. blot out--as from a register. transgressions--literally, "rebellions" (Ps 19:13 32:1).
2. Wash me--Purity as well as pardon is desired by true penitents. 3. For . . . before me--Conviction precedes forgiveness; and, as a gift of God, is a plea for it (2Sa 12:13 Ps 32:5 1Jo 1:9). 4. Against thee--chiefly, and as sins against others are violations of God's law, in one sense only. that . . . judgest--that is, all palliation of his crime is excluded; it is the design in making this confession to recognize God's justice, however severe the sentence. 5, 6. His guilt was aggravated by his essential, native sinfulness, which is as contrary to God's requisitions of inward purity as are outward sins to those for right conduct.
6. thou shalt make, &c.--may be taken to express God's gracious purpose in view of His strict requisition; a purpose of which David might have availed himself as a check to his native love for sin, and, in not doing so, aggravated his guilt. truth . . . and . . .wisdom--are terms often used for piety (compare Job 28:28 Ps 119:30).
7-12. A series of prayers for forgiveness and purifying. Purge . . . hyssop--The use of this plant in the ritual (Ex 12:22 Nu 19:6,18) suggests the idea of atonement as prominent here; "purge" refers to vicarious satisfaction (Nu 19:17-20). 8. Make . . . joy--by forgiving me, which will change distress to joy. 9. Hide, &c.--Turn from beholding. 10. Create--a work of almighty power. in me--literally, "to me," or, "for me"; bestow as a gift, a heart free from taint of sin (Ps 24:4 73:1). renew--implies that he had possessed it; the essential principle of a new nature had not been lost, but its influence interrupted (Lu 22:32); for Ps 51:11 shows that he had not lost God's presence and Spirit (1Sa 16:13), though he had lost the "joy of his salvation" (Ps 51:12), for whose return he prays. right spirit--literally, "constant," "firm," not yielding to temptation. 12. free spirit--"thy" ought not to be supplied, for the word "free" is, literally, "willing," and "spirit" is that of David. "Let a willing spirit uphold me," that is, with a soul willingly conformed to God's law, he would be preserved in a right course of conduct. 13. Then--Such will be the effect of this gracious work. ways--of providence and human duty (Ps 18:21,30 32:8 Lu 22:32).
15. open . . . lips--by removing my sense of guilt. 16. Praise is better than sacrifice (Ps 50:14), and implying faith, penitence, and love, glorifies God. In true penitents the joys of pardon mingle with sorrow for sin. 18. Do good, &c.--Visit not my sin on Thy Church. build . . . walls--is to show favor; compare Ps 89:40, for opposite form and idea. 19.God reconciled, material sacrifices will be acceptable (Ps 4:5; compare Isa 1:11-17).