31 This man has had three disciples, Thomas, and Baddas, and Hermas. Let none read the Gospel according to Thomas: for it is the work not of one of the twelve Apostles, but of one of the three wicked disciples of Manes. Let none associate with the soul-destroying Manicheans, who by decoctions of chaff counterfeit the sad look of fasting, who speak evil of the Creator of meats, and greedily devour the daintiest, who teach that the man who plucks up this or that herb is changed into it. For if he who crops herbs or any vegetable is changed into the same, into how many will husbandmen and the tribe of gardeners be changed? The gardener, as we see, has used his sickle against so many: into which then is he changed? Verily their doctrines are ridiculous, and fraught with their own condemnation and shame! The same man, being the shepherd of a flock, both sacrifices a sheep and kills a wolf. Into what then is he changed? Many men both net fishes and lime birds: into which then are they transformed?
Source: Catechetical Lectures (New Advent)