Albert Barnes Commentary Psalms 17:3

"Thou hast proved my heart; thou hast visited me in the night; Thou hast tried me, and findest nothing; I am purposed that my mouth shall not transgress." — Psalms 17:3 (ASV)

You have proved my heart - In this verse, he refers to his own character and life in the matter under consideration, or the consciousness of his own innocence regarding his fellow men who are persecuting and opposing him. He appeals to the Great Searcher of hearts as proof that, in this respect, he was innocent. He also refers to different forms of trial by God. These trials demonstrate that after the most thorough search, God would find (and indeed did find) that in these respects he was an innocent man, and that his enemies had no reason to treat him as they had done.

It is important to remember here that the trial the psalmist asks from God was not to prove that he was innocent toward God, or that he had a claim to God's favor because of his own personal holiness. Instead, it was to show that he was innocent of any wrongdoing toward those who were persecuting him. In other words, after the most searching trial, even by his Maker, it would be found that he had given them no cause for treating him thus.

The word translated here as “proved” means “to try, to prove, to examine,” especially metals, to test their genuineness (see Psalms 7:9-10, note; Job 12:11, note). The psalmist here says that God had tried or searched “his heart.” God knew all his motives and had examined all his desires and thoughts. The psalmist felt assured that, after the most thorough trial, even God would not find anything in his heart that would justify the conduct of his enemies toward him.

You have visited me - That is, for the purpose of inspecting my character, or of examining me. The English word “visit,” like the Hebrew, is often used to denote a visitation for the purpose of inspection and examination. The idea is that God had come to him for the very purpose of “examining” his character.

In the night - In solitude. In darkness. When I was alone. In the time when thoughts are less under restraint than when surrounded by others. In a time when it can be seen what we really are; when we do not put on appearances to deceive others.

You have tried me - The word used here—צרף (tsâraph)—properly means “to melt, to smelt,” etc., for metals, or separating the pure metal from the dross. The meaning is that God, in examining his character, had subjected him to a trial as searching as that employed in purifying metals by casting them into fire.

You shall find nothing - You will find nothing that could give occasion for the conduct of my enemies. The future tense is used here to denote that, even if the investigation were continued, God would find nothing in his heart or in his conduct that would warrant their treatment of him. He had the most full and settled determination not to do wrong to them in any respect whatever. Nothing had been found in him that would justify their treatment of him; he was determined so to live, and he felt assured that he would so live, that nothing of the kind would be found in him in the future. “I am purposed.” I am fully resolved.

My mouth shall not transgress - Transgress the law of God, or go beyond what is right. That is, I will utter nothing that is wrong, or that can give occasion for their harsh and unkind treatment. Much as he had been provoked and injured, he was determined not to retaliate, or to give occasion for their treating him in the manner in which they were now doing. Professor Alexander renders this, “My mouth shall not exceed my thought”; but the common version gives a better idea and is sanctioned by the Hebrew. (Compare Gesenius, Lexicon.)