The mention of the "fear of the Lord" prepares the way for the transition to the third part of the psalm. It is purely didactic, and, in its simple moral teaching and familiar contrast of the fates of righteous and ungodly, has affinities with the Book of Proverbs; but these are not so special as to require the supposition of contemporaneousness. It is unfashionable now to incline to the Davidic authorship; but would not the supposition that the "children," who are to be taught the elements of religion, are the band of outlaws who have gathered round the fugitive, give appropriateness to the transition from the thanksgiving of the first part to the didactic tone of the second? We can see them sitting round the singer in the half-darkness of the cave, a wild group, needing much control and yet with faithful hearts, and loyal to their leader, who now tells them the laws of his camp, at the same time as he sets forth the broad principles of that morality, which is the garment and manifestation among men of the "fear of the Lord." The relations of religion and morals were never more clearly and strikingly expressed than in the simple language of this psalm, which puts the substance of many profound treatises in a nutshell, when it expounds the "fear of Jehovah" as consisting in speaking truth, doing good, abhorring evil and seeking peace even when it seems to flee from us. The primal virtues are the same for all ages and stages of revelation. The definition of good and evil may vary and become more spiritual and inward, but the dictum that it is good to love and do good shines unalterable. The psalmist's belief that doing good was the sure way to enjoy good was a commonplace of Old Testament teaching, and under a Theocracy was more distinctly verified by outward facts than now; but even then, as many psalms show, had exceptions so stark as to stir many doubts. Unquestionably good in the sense of blessedness is inseparable from good in the sense of righteousness, as evil which is suffering is from evil which is sin, but the conception of what constitutes blessedness and sorrow must be modified so as to throw most weight on inward experiences, if such necessary coincidence is to be maintained in the face of patent facts.
The psalmist closes his song with a bold statement of the general principle that goodness is blessedness and wickedness is wretchedness; but he finds his proof mainly in the contrasted relation to Jehovah involved in the two opposite moral conditions. He has no vulgar conception of blessedness as resulting from circumstances. The loving-kindness of Jehovah is, in his view, prosperity, whatever be the aspect of externals. So with bold symbols, the very grossness of the letter of which shields them from misinterpretation, he declares this as the secret of all blessedness, that Jehovah's eyes are towards the righteous and His ears open to their cry. The individual experiences of vv. 5 and 6 are generalised. The eye of God--_i.e._ His loving observance--rests upon and blesses those whose faces are turned to Him, and His ear hears the poor man's cry. The grim antithesis, which contains in itself the seeds of all unrest, is that the "face of Jehovah"--_i.e._ His manifested presence, the same face in the reflected light of which the faces of the righteous are lit up with gladness and dawning glory--is against evil doers. The moral condition of the beholder determines the operation of the light of God's countenance upon him. The same presence is light and darkness, life and death. Evil and its doers shrivel and perish in its beams, as the sunshine kills creatures whose haunt is the dark, or as Apollo's keen light-arrows slew the monsters of the slime. All else follows from this double relationship.