Romans 9:31

Verse 31. But Israel. The Jews. The apostle does not mean to affirm that none of the Jews had obtained mercy, but that as a people, or acting according to the prevalent principles of the nation to work out their own righteousness, they had not obtained it. Which followed after the law of righteousness. The phrase, "the law of righteousness," means the law of justice, or the just law. That law demands perfect purity; and even its external observance demanded holiness. The Jews supposed that they rendered such obedience to that law as to constitute a meritorious ground of justification. This they had followed after; that is, pursued zealously and unremittingly.