The mouth of the righteous will speak wisdom As it is customary with hypocrites confidently to draw to their own advantage whatever the Spirit of God declares concerning the just and upright, David here gives a definition of the righteousness which God requires on the part of his children, and divides it into three principal parts -- that their speech should be in sincerity and truth; that the law of God should reign in their heart; and that they should order their conversation aright. Some give a different exposition of the first part from what 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; and, therefore, to speak wisdom, and to utter judgment, is, in their view, of the same import as to instruct others in holy doctrine, and to train them to the fear of God. I do not altogether disapprove of this exposition, but I fear it is too restricted. Wisdom and uprightness are here opposed as much to the profane and filthy language by which the wicked endeavor to blot out the name of God, as to cunning and fraud, and every species of stratagem and deceit; and also to the threats and terrors by which they endeavor to frighten the simple. The meaning therefore is, first, that the righteous speak honourably and reverently of the righteousness of God, that they may cherish in themselves and others, to a large extent, the knowledge and the 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 given to justify what is wrong under the color and varnish of sophistry; and, finally, that they never depart from the truth. To this there is added integrity of heart: The law of the Lord is in his heart. This, though it should precede in point of order, is not improperly put in the second place here. For the Scriptures are not particular in observing an exact arrangement in the enumeration of virtues and vices. Besides, the source whence this integrity of heart proceeds is, that the Law of God has its seat in the heart; and it is it alone which prescribes the best rule of life, restrains all the depraved affections and lusts, and imbues the minds of men with the love of righteousness. No man will constantly and steadily devote himself to a life of uprightness, exert himself in 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 endued with the fear of God. There next follows the third division, which relates to the 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 men, for the most part, too, endeavor, as far as in them lies, by 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 to their purpose with firm and determined resolution, or at least adhere to the right course.

The mouth of the righteous speaketh wisdom - That is, It is a characteristic of the righteous to speak "wise things;" not to utter folly. His conversation is serious, earnest, true, pure; and his words are faithful, kind, and just. This, as a part of human conduct, is one of the reasons why God will bless him with prosperity and length of days.
And his tongue talketh of judgment - That is, of just or righteous things. See Matthew 12:35.

The mouth of the righteous speaketh wisdom - Foolish and corrupt conversation cannot come out of their mouth. They are taught of God, and they speak according to the wisdom that is from above.

The (t) mouth of the righteous speaketh wisdom, and his tongue talketh of judgment.
(t) These three points are required from the faithful, that their talk is godly, that God's law is in their heart, and that their life is upright.

The mouth of the righteous speaketh wisdom,.... Or "meditateth wisdom" (a); that is, utters the wisdom he has been meditating upon; see Psalm 69:3; he meditates and speaks of the wisdom of God, which appears in the works of creation, providence, and grace; and of Christ, who is wisdom itself, and the wisdom of God essentially; and who, as Mediator, has the spirit of wisdom resting on him, the treasures of wisdom hid in him, and is made wisdom to his people: and righteous men meditate upon and speak of the glories of his person, the fulness of his grace, and the works of his hands; as also of the Gospel, which is the wisdom of God, mysterious, hidden, ancient wisdom, ordained before the world for their glory; and likewise of that internal wisdom, and experience of divine grace, the Lord has made them to know in the hidden part; which lies in the knowledge of themselves, and in a spiritual, experimental, and saving knowledge of Christ, and the way of salvation by him; and his mouth delivers out wise sayings, and useful instructions, fetched out of the word of God, and founded on experience and observation;
and his tongue talketh of judgment; of the judgment which the righteous God ordinarily ministers in a providential way; and of his extraordinary and awful judgments, which have been or are in the earth; these he takes notice of for his own use, and observes them to others for their instruction; and also of the last judgment, the judgment to come, which he speaks of as sure and certain, as universal and inevitable, and at which he must appear before God: and he talks of judgment or righteousness; that is, of the righteousness of Christ; he makes mention of this only as his justifying righteousness before God; he rejoices and glories in it, and desires to be found in it living and dying, and at judgment; and whatsoever things are honest, just, pure, and of good report, he thinks and speaks of them, and instructs his family, his children and servants, in them, that they may do them; see Genesis 18:19.
(a) Sept. "meditabitur", V. L. so Musculus: Junius & Tremellius, Piscator, Michaelis.

The righteous described as to the elements of character, thought, word, and action.

The verb הגה unites in itself the two meanings of meditating and of meditative utterance (vid., Psalm 2:1), just as אמר those of thinking and speaking. Psalm 37:31 in this connection affirms the stability of the moral nature. The walk of the righteous has a fixed inward rule, for the Tפra is to him not merely an external object of knowledge and a compulsory precept; it is in his heart, and, because it is the Tפra of his God whom he loves, as the motive of his actions closely united with his own will. On תּמעד, followed by the subject in the plural, compare Psalm 18:35; Psalm 73:2 Chethמb.

The mouth - Having shewed, God's singular care over the righteous, he proceeds to give a character of them. Judgment - Of God's judgment, word or law.