8 These men, however, deceive the people by the very Scriptures, that they may receive honors and praises at their hand, and that men may not turn to the truth. But in that they deceive, by the very Scriptures, the people of whom they seek honors, they do in fact sell oxen: they sell sheep too; that is, the common people themselves. And to whom do they sell them, but to the devil? For if the Church be Christ's sole and only one, who is it that carries off whatever is cut away from it, but that lion that roars and goes about, “seeking whom he may devour?” Woe to them that are cut off from the Church! As for her, she will remain entire. “For the Lord knows them that are His.” These, however, so far as they can, sell oxen and sheep, they sell doves too: let them guard against the scourge of their own sins. But when they suffer some such things for these their iniquities, let them acknowledge that the Lord has made a scourge of small cords, and is admonishing them to change themselves and be no longer traffickers: for if they will not change, they shall at the end hear it said, “Bind ye these men's hands and feet, and cast them forth into outer darkness.”
Source: Tractates on the Gospel of John (New Advent)