Romans 3:20

3:20 For no one is declared righteous before him ¹  by the works of the law, ²  for through the law comes ³  the knowledge of sin.

Romans 4:13

4:13 For the promise ⁴  to Abraham or to his descendants that he would inherit the world was not fulfilled through the law, but through the righteousness that comes by faith.

[3:20]  ¹ sn An allusion to Ps 143:2.

[3:20]  ² tn Grk “because by the works of the law no flesh is justified before him.” Some recent scholars have understood the phrase ἒργα νόμου (erga nomou, “works of the law”) to refer not to obedience to the Mosaic law generally, but specifically to portions of the law that pertain to things like circumcision and dietary laws which set the Jewish people apart from the other nations (e.g., J. D. G. Dunn, Romans [WBC], 1:155). Other interpreters, like C. E. B. Cranfield (“‘The Works of the Law’ in the Epistle to the Romans,” JSNT 43 [1991]: 89-101) reject this narrow interpretation for a number of reasons, among which the most important are: (1) The second half of v. 20, “for through the law comes the knowledge of sin,” is hard to explain if the phrase “works of the law” is understood in a restricted sense; (2) the plural phrase “works of the law” would have to be understood in a different sense from the singular phrase “the work of the law” in 2:15; (3) similar phrases involving the law in Romans (2:13, 14; 2:25, 26, 27; 7:25; 8:4; and 13:8) which are naturally related to the phrase “works of the law” cannot be taken to refer to circumcision (in fact, in 2:25 circumcision is explicitly contrasted with keeping the law). Those interpreters who reject the “narrow” interpretation of “works of the law” understand the phrase to refer to obedience to the Mosaic law in general.

[3:20]  ³ tn Grk “is.”

[4:13]  ⁴ sn Although a singular noun, the promise is collective and does not refer only to Gen 12:7, but as D. Moo (Romans 1-8 [WEC], 279) points out, refers to multiple aspects of the promise to Abraham: multiplied descendants (Gen 12:2), possession of the land (Gen 13:15-17), and his becoming the vehicle of blessing to all people (Gen 12:13).