John Gill Bible Commentary

I was also upright before him,.... In heart and conversation, being sincere and faithful; so David was in the sight of God; but this is much more true of Christ, in whom there was no unrighteousness nor guile, neither in his heart, nor in his lips; he was of perfect integrity, and faithful in all things to him that appointed him; and I kept myself from mine iniquity; which some interpret of original sin, in which David was born, which dwelt in him, and prompted him to sin; but rather it refers to the taking away of Saul's life, which he might be tempted to do, as being his enemy that sought his life; and which he was put upon and urged to by some about him, and yet did it not. But it is best here also to apply these words to Christ; for though he had no iniquity of his own, yet he had the iniquities of his people on him, as their surety, and which he calls "mine", Psa 40:12. But though he bore them, he did not commit any of them; though he was made sin, he knew none; and though he was tempted by Satan to the most enormous iniquities, as destroying himself and worshipping the devil, he kept himself from the evil one, that he could not touch him: the sense is, that he kept himself from committing any sin, which cannot be said of any mere man; and so far as good men are kept from sin, they are kept by the power of God, and not by themselves. All these things show, that the righteousness of Christ was a perfect, sinless one, entirely agreeable to the laws, statutes, and judgments of God; was pure in the sight of God, and rewardable in strict justice. Hence it is repeated as follows: