Ps 49:18

“To neglect these things any further, and to persevere in the former error, what is it else than to fall under the Lord's rebuke, who in the l psalm reproveth, and says, "What hast thou to do to declare my statutes, or that thou shouldest take my covenant into thy mouth, seeing thou hatest instruction and castest my words behind thee? When thou sawest a thief, thou consentedst with him, and hast been partaker with adulterers." For to declare the righteousness and the covenant of the Lord, and not to do the same that the Lord did, what else is it than to cast away His words and to despise the Lord's instruction, to commit not earthly, but spiritual thefts and adulteries? While any one is stealing from evangelical truth the words and doings of our Lord, he is corrupting and adulterating the divine precepts, as it is written in Jeremiah. He says, "What is the chaff to the wheat? Therefore, behold, I am against the prophets, saith the Lord, who steal my words every one from his neighbour, and cause my people to err by their lies and by their lightness." Also in the same prophet, in another place, He says, "She committed adultery with stocks and stones, and yet for all this she turned not unto me." That this theft and adultery may not fall unto us also, we ought to be anxiously careful, and fearfully and religiously to watch.”

“Most people, after all, do not simply give a verdict on their behavior from their own judgment but are also corrupted by the support of others. If sinners see everyone opposed, they believe they have committed some great crime; but if they see them not only showing no anger or irritation but exhibiting tolerance and joining forces with them, the tribunal of their conscience is then corrupted because the verdict of the majority supports their corrupt attitude. So what crime will they not attempt? When, on the contrary, will they condemn themselves and give up sinning unscrupulously? Thus it is essential that, in the case of people committing sin, they condemn themselves (this, you see, being the path to refraining from wickedness), and even if not practicing good, commend the good. The path to performance, after all, is willingness. Yet in this case, since there have been accomplices in crime, it is appropriate to apply the goad with great severity. After all, if evil flourishes to this extent even when reproved, and virtue, even when commended, has difficulty summoning its practitioners to the effort required, what would happen if these conditions did not apply?”

“"If thou sawest a thief, thou didst consent unto him, and with adulterers thou didst make thy portion." Lest perchance thou shouldest say, I have not committed theft, I have not committed adultery. What if he pleased thee that hath committed? Hast thou not with the very pleasing consented? Hast thou not by approval made thy portion with him that hath committed? For this is, brethren, to consent with a thief, and to make with an adulterer thy portion: for even if thou committest not, and approvest what is committed, thou art an accessory in the deed: for "the sinner is praised in the longings of his soul, and he that doeth iniquity shall be blessed." Thou doest not evil things, thou praisest evil-doers. For is this a small evil? "Thou didst make thy portion with adulterers."”

“"If you saw a thief, you ran with him." Here he sets forth the malice of sinners with respect to the commission of evil. But a little earlier he showed their defect with respect to the desertion of good, when he said, "But you have hated," etc. And first he sets forth their wickedness with respect to evil works; then with respect to evil words. He says, therefore, "If you saw." Where it should be known that these words are proposed in the person of God to the sinner who announces and preaches the justice of God. And they are especially suited to prelates and teachers, who do not easily fall into sin themselves, but consent to others who sin, and these things are turned against them. Rom. 1: "Not only those who do these things are worthy of death, but also those who consent," etc. 1 Sam. 2: "Eli was punished because he did not correct his sons." Therefore he reproves them for this. And he touches on two things, namely theft and adultery. With respect to the first he says, "If you saw a thief" brought before you for judgment, "you ran with him," not correcting him. Is. 1: "Your princes are faithless." Likewise, "with adulterers you placed your portion," because you do not correct adulterers, but flatter them and cover for them and support them when they come to your notice. Jer. 9: "They are all adulterers." But spiritual theft is when from the words of Sacred Scripture a corrupter steals the true meaning; and thus seeing someone corrupt and conceal the true meaning, and you consenting, you run with him. Jer. 23: "Behold, I am against the prophets who steal my words." Spiritual adultery is when words are twisted to another sense or to another end; for example, if someone preaches for gain or seduction. 2 Cor. 2: "We are not, as many, adulterating the word of God."”