2:21 Thou therefore who teachest another. Having just described the proud claims of the Jews, he next inquires how their practice corresponds.
Teachest thou not thyself? He who teaches others how to live, does he teach himself how to live?
Dost thou steal? Some of the essential principles of the law which the Jews supposed to teach to others. The decalogue forbade stealing (Ex 20:15), but the Jews were already proverbial for their tricky methods of trade.
2:21 Thou dost not teach thyself - He does not teach himself who does not practise what he teaches. Dost thou steal, commit adultery, commit sacrilege - Sin grievously against thy neighbour, thyself, God. St. Paul had shown the gentiles, first their sins against God, then against themselves, then against their neighbours. He now inverts the order: for sins against God are the most glaring in an heathen, but not in a Jew. Thou that abhorrest idols - Which all the Jews did, from the time of the Babylonish captivity. Thou committest sacrilege - Doest what is worse, robbing Him who is God over all of the glory which is due to him. None of these charges were rashly advanced against the Jews of that age; for, as their own historian relates, some even of the priests lived by rapine, and others in gross uncleanness. And as for sacrilegiously robbing God and his altar, it had been complained of ever since Malachi; so that the instances are given with great propriety and judgment.
2:17-24 The apostle directs his discourse to the Jews, and shows of what sins they were guilty, notwithstanding their profession and vain pretensions. A believing, humble, thankful glorying in God, is the root and sum of all religion. But proud, vain-glorious boasting in God, and in the outward profession of his name, is the root and sum of all hypocrisy. Spiritual pride is the most dangerous of all kinds of pride. A great evil of the sins professors is, the dishonour done to God and religion, by their not living according to their profession. Many despise their more ignorant neighbours who rest in a dead form of godliness; yet themselves trust in a form of knowledge, equally void of life and power, while some glory in the gospel, whose unholy lives dishonour God, and cause his name to be blasphemed.
