The natural conclusion from ver. 9 follows in the exhortation of ver. 10, which completes the positive presentation of the true object of trust (ver. 8) by the warning against false refuges. The introduction of "oppression" and "robbery" is singular, for it can scarcely be supposed that the assailants of the psalmist are here addressed, and still less that his followers needed to be warned against these crimes. Cheyne, therefore, follows Graetz and others in reading "perverseness" for "oppression," and "crookedness" for "robbery"; but the alteration throws the clause out of harmony with the next clause. It may be that in ver. 10 _a_ the psalmist has in view unjust gain and in _b_ justly acquired wealth, and that thus his two dehortations cover the whole ground of material riches, as if he had said, "Whether rightly or wrongly won, they are wrongly used if they are trusted in." The folly and misery of such trust are vigorously set forth by that word "become vain." The curse of misplaced confidence is that it brings down a man to the level of what he trusts in, as the blessing of wisely placed trust is that it lifts him to that level. Trust in vanity is vain, and makes the truster "vanity." Wind is not a nourishing diet. It may inflate, or, as Paul says about knowledge, may "puff up," but not "build up." Men are assimilated to the objects of their trust; and if these are empty, "so is every one that trusteth in them."
So far the psalmist has spoken. But his silent waiting has been rewarded with a clear voice from heaven, confirming that of his faith. It is most natural to regard the double revelation received by the psalmist as repeated in the following proclamation of the two great aspects of the Divine nature--Power and Loving-kindness. The psalmist has learned that these two are not opposed nor separate, but blend harmoniously in God's nature, and are confluent in all His works. Power is softened and directed by Loving-kindness. Loving-kindness has as its instrument Omnipotence. The synthesis of these two is in the God whom men are invited to trust; and such trust can never be disappointed; for His Power and His Loving-kindness will co-operate to "render to a man according to his work." The last word of the psalm adds the conception of Righteousness to those of Power and Loving-kindness. But the psalmist seems to have in view mainly one direction in which that rendering "to a man according to his work" is active--namely, in answering the trust which turns away from human power which is weakness, and from human love which may change and must die, to anchor itself on the might and tenderness of God. Such "work of faith" will not be in vain; for these twin attributes of Power and Love are pledged to requite it with security and peace.