The details of the qualifications as described in the psalm are simple and homely. They relate first to right speech, which holds so prominent a place in the ethics of the Psalter. The triplets of ver. 3 probably all refer to sins of the tongue. The good man has no slander on his tongue; he does not harm his companion (by word) nor heap reproach on his neighbour. These things are the staple of much common talk. What a quantity of brilliant wit and polished sarcasm would perish if this rule were observed! How dull many sparkling circles would become, and how many columns of newspapers and pages of books would be obliterated, if the censor's pencil struck out all that infringed it! Ver. 4 adds as characteristic of a righteous man that in his estimate of character he gives each his own, and judges men by no other standard than their moral worth. The reprobate may be a millionaire or a prince, but his due is contempt; the devout man may be a pauper or one of narrow culture, but his due is respect, and he gets it. "A terrible sagacity informs" the good man's heart; and he who is, in his own inmost desires, walking uprightly will not be seduced into adulation of a popular idol who is a bad man, nor turned from reverence for lowly goodness. The world will be a paradise when the churl is no more called bountiful.
Apparently the utterance of these estimates is in the psalmist's mind, and he is still thinking of speech. Neither calumny (ver. 3) nor the equally ignoble flattery of evil-doers (ver. 4) pollutes the lips of his ideal good man. If this reference to spoken estimates is allowed, the last clause of ver. 4 completes the references to the right use of speech. The obligation of speaking "truth with his heart" is pursued into a third region: that of vows or promises. These must be conceived as not religious vows, but, in accordance with the reference of the whole psalm to duties to neighbours, as oaths made to men. They must be kept, whatever consequences may ensue. The law prohibited the substitution of another animal sacrifice for that which had been vowed (Lev. xxvii. 10); and the psalm uses the same word for "changeth," with evident allusion to the prohibition, which must therefore have been known to the psalmist.
Usury and bribery were common sins, as they still are in communities on the same industrial and judicial level as that mirrored in the psalm. Capitalists who "bite" the poor (for that is the literal meaning of the words for usurious taking of interest) and judges who condemn the innocent for gain are the blood-suckers of such societies. The avoidance of such gross sin is a most elementary illustration of walking uprightly, and could only have been chosen to stand in lieu of all other neighbourly virtues in an age when these sins were deplorably common. This draft of a God-pleasing character is by no means complete even from the Old Testament ethical point of view. There are two variations of it, which add important elements: that in Psalm xxiv., which seems to have been occasioned by the same circumstances; and the noble adaptation in Isa. xxxiii. 13-16, which is probably moulded on a reminiscence of both psalms. Add to these Micah's answer to the question what God requires of man (ch. vi. 8), and we have an interesting series, exhibiting the effects of the Law on the moral judgments of devout men in Israel.
The psalmist's last word goes beyond his question, in the clear recognition that such a character as he has outlined not only dwells in Jehovah's tent, but will stand unmoved, though all the world should rock. He does not see how far onward that "for ever" may stretch, but of this he is sure: that righteousness is the one stable thing in the universe, and there may have shone before him the hope that it was possible to travel on beyond the horizon that bounds this life. "I shall be a guest in Jehovah's tent for ever," says the other psalm already quoted; "He shall never be moved," says this one. Both find their fulfilment in the great words of the Apostle who taught a completer ideal of love to men, because he had dwelt close by the perfect revelation of God's love: "The world passeth away, and the lust thereof, but he that doeth the will of God abideth for ever."