Psalms 40:11,12 - Joseph Benson’s Commentary on the Old and New Testaments

Withhold not thy tender mercies, &c. This prayer is uttered by David, either, 1st, In the person of Christ, to whom it may agree; or, rather, 2d, In his own person. For having been transported by the Spirit of God to the commemoration of the great mystery of the Messiah, of whom he was an illustrious type, he now seems to be led back by the same Spirit to the consideration of his own case. Mine iniquities Either, 1st, The punishment of mine iniquities, as Genesis 4:13, and elsewhere; or, 2d, The iniquities themselves. This cannot be understood of Christ. For although our sins were said to be laid upon him, Isaiah 53:6, and upon that account he is said to be made sin for us, 2 Corinthians 5:21; yet the Scripture everywhere represents him as one that never knew or did any sin; and, therefore, it is not probable that the Holy Ghost would use such an expression concerning him, as is never used in Scripture, but either of a man's own sins, or of the punishment deserved by them. Have taken hold upon me Men's sins are figuratively said to follow them, 1 Timothy 5:24, and to find them out, Numbers 32:23; and here to take hold on them as an officer takes hold on a man, whom he arrests. So that I am not able to look up Unto God or men with any comfort or confidence; I am ashamed and confounded. They are more than the hairs of my head Namely, mine iniquities here mentioned, properly so called; for God's people are more apt to aggravate their sins than the punishments of them.