John Calvin Commentary Psalms 37:30

"The mouth of the righteous talketh of wisdom, And his tongue speaketh justice." — Psalms 37:30 (ASV)

The mouth of the righteous will speak wisdom. As it is customary for hypocrites to confidently use for their own advantage whatever the Spirit of God declares concerning the just and upright, David here gives a definition of the righteousness that God requires from His children. He divides it into three principal parts — that their speech should be sincere and truthful; that the law of God should reign in their hearts; and that they should order their conduct rightly.

Some offer a different exposition of the first part than the one we have given. They say that the righteous serve as teachers and guides by instructing others to live well and leading them in the way. Therefore, to speak wisdom and to utter judgment is, in their view, equivalent to instructing others in holy doctrine and training them in the fear of God.

I do not entirely disapprove of this exposition, but I fear it is too restricted. Wisdom and uprightness are here contrasted as much with the profane and filthy language by which the wicked endeavor to blot out the name of God, as with cunning and fraud, and every kind of stratagem and deceit, and also with the threats and terrors by which they endeavor to frighten the simple.

The meaning, therefore, is: first, that the righteous speak honorably and reverently of the righteousness of God, so that they may greatly cherish in themselves and others the knowledge and fear of God; secondly, that both in their own affairs and those of others, they approve, without disguise or deceit, of what is just and reasonable, and are not inclined to justify what is wrong under the guise and gloss of sophistry; and finally, that they never depart from the truth.

To this is added integrity of heart: The law of the Lord is in his heart. Although this should precede in logical order, it is not improperly placed second here. For the Scriptures are not always particular about observing an exact arrangement in listing virtues and vices.

Besides, the source from which this integrity of heart proceeds is that the Law of God resides in the heart; and it alone prescribes the best rule of life, restrains all depraved affections and lusts, and imbues human minds with the love of righteousness.

No one will constantly and steadily devote himself to a life of uprightness, exert himself on behalf of others in preference to his own personal interests, renounce covetousness, subdue pride, and maintain a constant warfare with his own nature, unless he is endowed with the fear of God. Next follows the third division, which relates to external conduct: His steps shall not slide. Some, indeed, think that this is a promise, but I have no doubt that in this clause David still continues the definition of righteousness.

The meaning, therefore, is that although the children of God are tempted in a variety of ways to commit sin, and many things occur urging them to it, — and although people, for the most part, also endeavor, as much as they can, with their maliciousness to turn them aside from the fear of God — yet, because the Law of God rules and reigns in their hearts, they do not slide, but stand firm in their purpose with resolute determination, or at least adhere to the right course.