Charles Ellicott Commentary Psalms 18:25-27

"With the merciful thou wilt show thyself merciful; With the perfect man thou wilt show thyself perfect; With the pure thou wilt show thyself pure; And with the perverse thou wilt show thyself froward. For thou wilt save the afflicted people; But the haughty eyes thou wilt bring down." — Psalms 18:25-27 (ASV)

It is better to change all the futures into our present. We cannot explain this description of God’s attitude to humanity as if the poet were merely dealing with the conception of the Divine formed in the human heart. No doubt his words are amply true in this sense. The human heart makes its God like itself, and to the pure and just He will be a pure and just God, to the cruel and unjust, cruel and unjust. But the definite mention of recompense in Psalm 18:24, and the reference to active interposition on behalf of the just in Psalm 18:27, leave us no option but to understand by shew thyself in Psalm 18:25-26, not an inward conception, but an external manifestation.

It is, in fact, nothing more than a restatement of the truth of which the history of Pharaoh is the most signal historic declaration, and which we maintain whenever we speak of the natural consequences of sin as retributive justice—the truth which is summed up in the text, whatsoever a man soweth, that shall he also reap. We must at the same time remember that the form of the statement in the psalm is due to the view current in Israel before the development of the conception of Satanic agency, that all suggestions, evil as well as good, came from the mind of the Supreme Disposer of events.