John Calvin Commentary Psalms 40:12

"For innumerable evils have compassed me about; Mine iniquities have overtaken me, so that I am not able to look up; They are more than the hairs of my head; And my heart hath failed me." — Psalms 40:12 (ASV)

For innumerable evils have compassed me on all sides. This phrase, in the original, denotes more than can be expressed in an English translation; for he says, עלי alay, upon me, meaning by this that he was not only beset on all sides, but also that an accumulation of evils pressed upon his head.

He, however, does not now complain of being punished unjustly, or more than he deserves, but rather confesses plainly that it is the just recompense of his sins which is rendered to him. For although the word עון, avon, which we have rendered iniquity, also signifies the punishment of iniquity (as we have seen elsewhere more than once); yet we must take into consideration the derivation of the word.

Accordingly, since David calls the afflictions he endures the fruit or effect of his transgressions, there is implied in this a humble confession, from which we may ascertain with what reverence and meekness he submitted to the judgments of God, given that, when overwhelmed with an accumulation of miseries, he sets forth his sins in all their magnitude and aggravation, lest he should suspect God of undue severity.

When we see David treated so severely, let us also learn, when we are oppressed with extreme afflictions and are groaning under them, to humbly implore the grace and mercy of our Judge. Nor is it his intention to show that he had been foolish or hardened when he says that his heart failed or forsook him. His language means that he was not only broken-hearted, but that he lay as if he were dead.

We must, however, understand this fainting or failing of the heart as referring to the experience of his human nature; for his perseverance in prayer is a certain proof that his faith was never altogether extinguished. But since, humanly speaking, he was destitute of counsel and was altogether without strength, it is not without cause that he says his heart failed him.