The Apostle Paul
Romans 2:17ESV·traditional attribution

But if you call yourself a Jew and rely on the law and boast in God

John Calvin Reformed @genevareformer

17. Behold, thou art named a Jew, etc. Some old copies read εἰ δὲ, though indeed; which, were it generally received, would meet my approbation; but as the greater part of the manuscripts is opposed to it, and the sense is not unsuitable, I retain the old reading, especially as it is only a small difference of one letter. Griesbach has since found a majority of MSS.

Matthew Henry Presbyterian @wholebiblehenry

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

John Gill Reformed Baptist @doctorgill

And art confident that thou thyself,.... Being vainly puffed up in, their fleshly minds, they were strongly persuaded that they were very fit persons to be a guide to the blind: all men are by nature blind, as to the knowledge of divine and spiritual things; the meaner sort of the people among the Jews seem to be intended here; or else the ignorant Gentiles...