Thou who abhorrest idols, etc. He fitly compares sacrilege to idolatry, as it is a thing of the same kind; for sacrilege is simply a profanation of the Divine Majesty, a sin not unknown to heathen poets. On this account Ovid (Metamor. 3,) calls Lycurgus sacrilegious for despising the rites of Bacchus; and in his Fasti he calls those sacrilegious hands which violated the majesty of Venus. But as the Gentiles ascribed the majesty of their gods to idols, they only thought it a sacrilege when any one plundered what was dedicated to their temples, in which, as they believed, the whole of religion centered. So at this day, where superstition reigns, and not the word of God, they acknowledge no other kind of sacrilege than the stealing of what belongs to churches, as there is no God but in idols, no religion but in pomp and magnificence. [1] Now we are here warned, first, not to flatter ourselves and to despise others, when we have performed only some portions of the law, -- and, secondly, not to glory in having outward idolatry removed, while we care not to drive away and to eradicate the impiety that lieth hid in our hearts.

Footnotes

1 - "Sacrilege," mentioned here, is by some taken literally as meaning the robbing of God as to the sacrifices he required, and the profanation of sacred rites; "many examples of which," says Turrettin, "are recorded by the Prophets, and also by Josephus, both before and during the last war." But some extend its meaning to acts of hypocrisy and ungodliness, by which God's honor was profaned, and the glory due to him was denied. The highest sacrilege, no doubt, is to deprive God of that sincere service and obedience which he justly requires. "They caused," says Pareus, "the name and honor of God to be in various ways blasphemed by their wicked hypocrisy; and hence they were justly said by the Apostle to be guilty of sacrilege." He then adds, "we must notice, that idolatry is not opposed to sacrilege, but mentioned as a thing closely allied to it. Indeed all idolatry is sacrilegious. How then can the Monks, Priests, and Jesuits clear themselves from the charge of sacrilege? for they not only do not detest idolatry, being in this respect much worse than these hypocrites, but also greedily seek, like them, sacred offerings, and under the pretense of sanctity devour widows' houses, pillage the coffers of kings, and, what is most heinous, sacrilegiously rob God of his due worship and honor and transfer them to saints." Yet the world is so blind as not to see the real character of such men! -- Ed.

Dost thou commit adultery? - There is no doubt that this was a crime very common among the Jews; see the Matthew 12:39 note; John 8:1-11 notes. The Jewish Talmud accuses some of the most celebrated of their Rabbies, by name, of this vice. (Grotius.) Josephus also gives the same account of the nation.
Thou that abhorrest idols - It was one of the doctrines of their religion to abhor idolatry. This they were everywhere taught in the Old Testament; and this they doubtless inculcated in their teaching. It was impossible that they could recommend idolatry.
Dost thou commit sacrilege? - Sacrilege is the crime of violating or profaning sacred things; or of appropriating to common purposes what has been devoted to the service of religion. In this question, the apostle shows remarkable tact and skill. He could not accuse them of idolatry, for the Jews, after the Babylonish captivity, had never fallen into it. But then, though they had not the form, they might have the spirit of idolatry. That spirit consisted in withholding from the true God what was his due, and bestowing the affections upon something else. This the Jews did by perverting from their proper use the offerings which were designed for his honor; by withholding what he demanded of tithes and offerings; and by devoting to other uses what was devoted to him, and which properly belonged to his service. That this was a common crime among them is apparent from Malachi 1:8, Malachi 1:12-14; Malachi 3:8-9. It is also evident from the New Testament that the temple was in many ways desecrated and profaned in the time of our Saviour; notes, Matthew 21:12-13.

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? an iniquity which greatly prevailed among the Jews at this time of day; hence Christ calls them "an adulterous generation", Matthew 12:39; and that to such a degree, that by the advice of their great Rabbi, R. Jochanan ben Zaccai, they left off the trial of the suspected woman, cases of this nature being so very numerous: and this sin prevailed not only among the common people, but among their principal doctors; as may be learnt from their own writings, and from that conviction of this iniquity which the Scribes and Pharisees were brought under by Christ, when the woman, taken in adultery, was had before him by them, John 8:9.
Thou that abhorrest idols, dost thou commit sacrilege? for though at this time they abhorred idolatry, to which their forefathers were so much inclined, and so often fell into, yet they were guilty of sacrilege; by violating the worship of God, and polluting it with their own inventions; by pillaging or withholding, or not offering the sacrifices they ought; and by plundering the temple, and converting the sacred things of it to their own use.

thou that abhorrest idols--as the Jews did ever after their captivity, though bent on them before.
dost thou commit sacrilege?--not, as some excellent interpreters, "dost thou rob idol temples?" but more generally, as we take it, "dost thou profane holy things?" (as in Matthew 21:12-13, and in other ways).