For. Moses describeth the righteousness which is of the law,.... In this, and some following verses, an account is given of the two righteousnesses before mentioned, called their own and the righteousness of God; and that chiefly in the words of Moses, which is wisely done by the apostle, he and his writings being in great esteem among the Jews.
The description he gives of the righteousness of the law, that is, righteousness which the law requires, and is done in obedience to its commands, is,that the man which doth those things, shall live by them, or "in them"; and which is to be seen in Le 18:5: "ye shall therefore keep my statutes and my judgments, which if a man do, he shall live in them"; from whence it appears, that by "those things" a man is to do, are meant the statutes and judgments of God, not the ordinances of the ceremonial, but the precepts of the moral law; and that the righteousness of the law lies in "doing" and keeping those statutes, not merely externally, but internally, with all the heart, and soul, and strength; the law requires love to God, fear of him, and faith in him, and an inward disposition of the mind towards him, and a conformity of heart and nature to his law, as well as outward obedience; and all this is to be done perfectly and completely in every punctilio the law requires, otherwise no life is to be expected, nor any righteousness to be had by it.
The Jewish writers understand the life promised by the law, to be eternal life. The two Targums of Onkelos and Jonathan ben Uzziel paraphrase the words thus, "he shall live in them", amle yyxb, "in eternal life"; in like manner Jarchi explains them, "he shall live", abh Mlwel, "in the world to come"; to which agrees the note of R.
Aben Ezra, who interprets it of lie in both worlds; he says the statutes of the law are life to them that do them in both worlds, for if a man understands the secret of them, he shall live for ever, and shall never die.