John Nelson Darby wrote:
Psalm 17 considers this life practically here below and in respect to its difficulties with man opposed to what is right. The state of the soul is still marked by entire dependence on God, but, as to integrity towards God, and as against man, the soul can plead righteousness. Still it does not avenge itself, but casts itself entirely on God, and thus gets the fruits of His righteous dealings. This is a great secret of practical wisdom not avenging self - the patience of the new life in the midst of evil, and looking, and leaving all to God. This supposes the righteous path as man of the divine life, which therefore can appeal to God's necessary judgment about it, knowing what He is, and also trusting in Him; but even here deliverance is sought, not vengeance, only the disappointing the plans of wickedness. If we have not walked uprightly, still confidence in God is our true place. He spares and restores in mercy most graciously; but this, though other psalms take it up, is not the subject of this psalm. Here it is the righteous life which God looks at and vindicates against the men of this world, for it is Christ, and Christians as far as they live the life of Christ. Immediately, as ever, it is Christ and the remnant. Jehovah hears the righteous, and the prayer which goes not out of feigned lips.
Remark, that in this psalm the life of Christ is supposed and found to meet opposition, and oppression in the world from the men of this world. We have seen how separated it was, associated with the excellent of the earth, passing as a stranger through it, though humanly in it. But then faith - and this shews how entirely Jehovah is still looked to - sees that the men of this world are the men of God's hand. They serve to prove the heart, and, in us who are ever in danger to slip into the world, to keep us strangers in it. Still God delivers from them, Christ, for blessed reasons, was not delivered, yet as freely giving Himself. The heart has the sense of righteousness here, and hence counts on deliverance; but there is no spirit of vengeance. It is the Spirit of Christ Himself, and hence above the spirit of the remnant, and much more the Christian spirit. There is the consciousness of righteousness and of integrity, but entire dependence on the Lord in respect of it, not as regards justification - it is not the question here - but confidence. "I know nothing of myself," says Paul, "yet am I not hereby justified." Again, "if our heart condemn us not, then have we confidence towards God." So Jesus: "The Father hath not left me alone, for I do always those things that please him." There is the consciousness of righteousness and confidence in God. And the heart appeals to Him, because of righteousness. And all this is right, thinks rightly of God, and trusts to God that He will not be inconsistent with Himself, and cannot be. If there be desire of vengeance, we have sunk below this.
Practical Reflections on the Psalms