an instructor of the foolish, a teacher of infants, because you have in the law the embodiment of knowledge and truth—
20. I take what follows, having the form of knowledge, as a reason for the preceding; and it may be thus explained, — “because thou hast the form of knowledge.” For they professed to be the teachers of others, because they seemed to carry in their breasts all the secrets of the law.
In the latter part of the chapter the apostle directs his discourse more closely to the Jews, and shows what sins they were guilty of, notwithstanding their profession and vain pretensions. He had said (Rom 2:13) that not the hearers but the doers of the law are justified; and he here applies that great truth to the Jews. Observe, I.
Commenting on Romans 2:17-29
Thou that sayest a man should not commit adultery,.... Adultery here is to be taken not figuratively for adulterating the word of God, and mixing it with their own inventions; but literally for the sin of adultery, and that not in heart only, but in act: dost thou commit adultery?