John Chrysostom, on Titus 1:10

Ver. 10. "For there are many unruly and vain talkers and deceivers, especially they of the circumcision;"

Ver. 11. "Whose mouths must be stopped."

Seest thou how he shows that they are such? From their not wishing to be ruled, but to rule. For he has glanced at this. When therefore thou canst not persuade them, do not give them charges, but stop their mouths, for the benefit others. But of what advantage will this be, if they will not obey, or are unruly? Why then should he stop their mouths? In order that others may be benefited by it.

"Who subvert whole houses, teaching things which they ought not for filthy lucre's sake."

For if he has undertaken the office of a Teacher, and is not able to combat these enemies, and to stop their mouths who are so shameless, he will become in each case the cause of their destination who perish. And if some one has thus advised, "Seek not to be a judge, unless thou canst take away iniquity" (Ecclus. vii. 6); much more may we say here, "Seek not to be a Teacher, if thou art unequal to the dignity of the office; but though dragged to it, decline it." Dost thou see that the love of power, the love of for filthy lucre, is a cause of these evils? "Teaching things which they ought not," he says, "for filthy lucre's sake."