Didymus the Blind : The snake is powerful, when it spreads its poison secretly. In the one who is tricked, an impression is created that he has received something good which in reality is not good. The teacher who charms should not do so in a superflous way but in a way that accomplishes something. Then he shows his [student] the error, the guile of his seducer. — COMMENTARY ON Ecclesiastes 304:20 Jerome : "If the snake bites because it has not been charmed, then there is no advantage to the charmer's art. "The meaning of this is very apparent: the serpent and the disparager are of the same ilk. For just as the hidden snake bites and injects its poison, so too the other disparages in private, and he pours out the poison of his heart against his brother, and there will be nothing between him and the serpent. For although the tongue of man was created for benediction and encouragement of others, the disparager makes it equal to that of the serpent, while he uses his virtues to bad purposes. Another meaning of this is, that if the serpent devil should bite anyone secretly, and he doesn't know it, he infects him with the poison of sin; and if he who has been struck keeps silent, and does not repent, and does not want to confess his wound to his teacher and brother, they who want to encourage him and see to it that he gets better, are not able to be of any use to him. For if an ill man is ashamed to confess his wound to a doctor, the doctor will not be able to cure what he does not know exists. — Commentary on Ecclesiastes John Cassian : "If a snake bites without hissing," Ecclesiastes says, "there is no advantage for the charmer," showing that the bite of a snake in silence is dangerous. This means that if a suggestion or thought springing from the devil is not by means of confession shown to some charmer (I mean some spiritually minded person who knows how to heal the wound at once by charms from the Scripture and how to extract the deadly poison of the snake from the heart), it will be impossible to help the sufferer who is already in danger and will no doubt die. — CONFERENCE 2:9 John Cassian : These silent bites are alone in fending off the medicine of the wise people. This deadly menace is so utterly incurable that it is worsened by soothings, inflamed by serious treatment, and irritated by gifts. — CONFERENCE 18:16