But, O Lord, that triest the righteous, and seest the reins and the heart,.... That tries the cause of the righteous, and vindicates them, rights their wrongs, and does them justice; being the omniscient God, the seer and searcher of the hearts and reins; who knows the uprightness of their hearts, as well as their ways, and the sincerity of their affections: or that tries the faith and patience of the righteous, their constancy and integrity; and upon trial finds that their affections are real, and their souls sincere;let me see thy vengeance on them; his enemies and persecutors; he does not seek vengeance himself, but desires it of the Lord; he does not ask to see his vengeance, but the Lord's vengeance on them, what he thought was just and proper to inflict on them; he knew that vengeance belonged to the Lord, and therefore left it with him, and prayed for it from him.
The Targum is,"let me see the vengeance of thy judgments on them;''for unto thee have I opened my cause; or "revealed", or "made it manifest" ; this he did in prayer, at this time, when he laid before the Lord his whole case, and appealed and applied to him for justice, who judgeth righteous persons, and judgeth righteously.
ybyr ta ytylg "revelavi causam meam", Junius & Tremellius, Piscator.