Psalms 119:106

106.I have sworn, and will perform Here the Psalmist speaks of his own constancy. He had declared a little before, that during the whole course of his life, he had not declined from God’s law, and now he speaks of the purpose of his mind. By the word swear, he intimates that he had solemnly pledged himself to God not to alter his determination. The true manner of keeping God’s law is to receive and embrace what he commands heartily, and, at the same time, uniformly, that our ardor may not forthwith abate, as is often the case. This also is the proper rule of vowing, that we may offer ourselves to God, and dedicate our life to him. It may, however, be asked, whether the prophet’s oath may not be condemned as rash, inasmuch as he presumed to engage to do far more than man’s ability is equal to; for who is able to keep the law? The man, then, it may be alleged, vows rashly, who promises to God a thing which it is beyond his power to accomplish. The answer is obvious: Whenever the faithful vow to Him, they do not look to what they are able to do of themselves, but they depend upon the grace of God, to whom it belongs to perform what he requires from them, in the way of supplying them with strength by his Holy Spirit. When the question is in reference to service to be rendered to God, they cannot vow anything without the Holy Spirit; for, as Paul says in 2 Corinthians 3:5 ,

“ Not that are sufficient of ourselves to think anything
as of ourselves.”

But when God stretches forth his hand to us, he bids us be of good courage, and promises that he will never fail us; and this is the source from which the boldness to swear, here spoken of, proceeds. Nor is it any rashness at all, when, confiding in his promises, by which he anticipates us, we, on our part, offer ourselves to his service. The question, however, still remains unsolved; for although the children of God ultimately prove victorious over all temptations by the grace of the Holy Spirit, yet there is always some infirmity about them. But it is to be observed, that the faithful, in making vows and promises, have a respect not only to that article of the covenant, by which God has promised that he will cause us to walk in his commandments, but also to that other article which is, at the same time, added concerning the free forgiveness of their sins, Ezekiel 11:20; Psalms 103:13. David, therefore, according to the measure of grace given him, bound himself by oath to keep God’s la encouraged by these words of the prophet,

“I will spare them, as a man spareth his own son that serveth him,”
Malachi 3:17.