Psalms 5:9

9.For there is no faithfulness in their mouth. He still repeats the same complaints which he made before, in order thereby to render his enemies the more odious in the sight of God, and to call forth in his own behalf the mercy of God, who has promised to succor those who are unjustly oppressed. And this is to be particularly attended to, that the more our enemies manifest their cruelty against us, or the more wickedly they vex us, we ought, with so much the greater confidence, to send up our groanings to heaven, because God will not suffer their rage to proceed to the uttermost, but will bring forth their malice and wicked devices to the light. In the first place, he accuses them of treachery, because they speak nothing uprightly, or in sincerity; and the cause which he assigns for this is, that inwardly they are full of iniquity. He next compares them to sepulchres, their throat is an open sepulcher; as if he had said, they are devouring gulfs; (76) meaning by this, their insatiable desire of shedding blood. In the close of the verse, he again speaks of their deceitfulness. From all this we conclude, that the wrongs with which he was tried were of no ordinary kind, but that he had to contend with enemies the most wickedly who had neither humanity nor moderation. Being so miserably oppressed, he not only perseveres in prayer, but finds ground of hope even from the confusion and apparent hopelessness of his outward condition.

When Paul, (Romans 3:13,) in quoting this passage, extends it to all mankind, both Jews and Gentiles, he does not give to it a meaning of greater latitude than the Holy Spirit intended to give. Since he takes it as an undeniable point, that under the person of David, there is here described to us the church, both in the person of Christ, who is the head, and in his members, it follows that all those ought to be reckoned among the number of his enemies, who have not been regenerated by the Spirit of God, whether they are without the pale of the visible church, or within it. For David, in this passage, does not summons either the Assyrians or the Egyptians to the judgment-seat of God, but the degenerate Jews, who, being circumcised in the flesh, gloried in their descent from the holy lineage of Abraham. Paul, therefore, does not wrest these words from their genuine meaning when he applies them to all mankind, but asserts, with truth, that David showed in them what is the character of the whole human family by nature.