John Calvin Commentary Psalms 119:104

"Through thy precepts I get understanding: Therefore I hate every false way. NUN." — Psalms 119:104 (ASV)

By your statutes I have acquired understanding. The prophet seems here to invert the order he has just laid down. He observed that he had kept his feet from going astray, so that he might observe God’s Law, and now he establishes a contrary order, beginning with the observance of the Law; for he declares that he had been taught by the word of God before he amended his faults.

Yet these two things are not inconsistent—that the faithful should withdraw from their wanderings to frame their life according to the rule of God’s word, and that when they are already advanced a considerable way in a holy life, the fear of God then being more vigorous in them, they should regard all vices with more intense hatred.

The beginning of a good life, unquestionably, is when a man endeavors to purge himself from vices; and the more a man has made progress in a good life, he will burn with a proportionate zeal in his detestation of vices and in shunning them. Moreover, we are taught by the words of the prophet that the reason why men are so involved in falsehoods and entangled in perverse errors is because they have not learned wisdom from the word of God.

As the whole world is given to folly, those who wander astray plead as an excuse that it is difficult for them to guard against the allurements of vice. But the remedy will be close at hand if we follow the counsel of the prophet; that is, if, instead of leaning on our own wisdom, we seek understanding from the word of God, in which he not only shows what is right but also fortifies our minds and puts us on our guard against all the deceits of Satan and all the impostures of the world.

Would to God that, in the present day, this were thoroughly impressed on the minds of all who boast of being Christians; for then they would not be continually driven about, as the greater part of them are, with such inconstancy, according to the conflicting impulses of prevailing opinions. As Satan is so diligently exerting himself to spread the mists of error, let us apply ourselves with greater earnestness to the acquisition of this wisdom.