John Gill Bible Commentary

Search me, O God, and know my heart,.... He had searched him, and knew his heart thoroughly; try me, and know my thoughts; he had tried him, and knew every thought in him, Psa 139:1. This therefore is not said for the sake of God; who, though he is the trier of hearts, and the searcher of the reins, is indeed a discerner of the thoughts and intents of the heart at once, and knows immediately what is in man; and needs no testimony of him, nor to make use of any means in order to know him and what is within him: but David said this for his own sake, that God would search and make known to him what was in his heart, and try him by his word, as gold is tried in the fire; or by anything difficult and self-denying, as he tried Abraham; or by any afflictive providence; or in any way he thought fit to make him acquainted thoroughly with himself. His sense is this, that if he knew his own heart and thoughts, and the inward frame and disposition of his soul, it was as he had expressed it; that he was grieved with sinners, and hated those that hated the Lord, even with a perfect hatred, and reckoned them as his enemies; but if it was otherwise, he desired to be searched and tried thoroughly, that it might be discovered: and he might say this also on account of others, who charged him falsely with things he was not conscious of; that never entered into his thoughts, and his heart knew nothing of, and could not accuse him with; and therefore he appeals to the heart searching God, that he would so lay open things that his integrity and innocence might appear to all; see Gen 22:1.