Cyril of Jerusalem

The heretics do this by coating over their poison pills of godless doctrines with the honey of the name of Christ.

Catechetical Lecture 4.2 ↗

Theophylact of Ohrid

Withdraw from them, he says. If they were doing this out of ignorance or error, they would need to be corrected. But since they sin deliberately, flee from them. He hints at the Jews, whom he customarily reproaches as gluttons; for such is their entire race. Furthermore, all heresies are born from the service of passions and the belly. How then are you not ashamed, being a brother of Christ, to make slaves of the belly your teachers? Note, moreover, that he who serves the belly does not serve Christ. …

Commentary on Romans ↗

Jerome

Flattery is always insidious, deceitful and bland. And a flatterer is well defined by philosophers as a bland enemy. Truth is harsh, bitter, stern, unpleasant and offensive to those who are reproved.

Against the Pelagians 1.26 ↗

Thomas Aquinas

Then when he says, for they who, he assigns two reasons for what he had said, the first of which is taken on the part of those whom he wants avoided. First, he describes their condition, saying: for they who are such serve not Christ but their own belly. For they preached not for the glory of Christ but for revenue, in order to fill their belly: for many, of whom I have often told you and now tell you even with tears, live as enemies of the cross of Christ. Their god is their belly (Phil 3:18). …

Commentary on Romans ↗