Origen
Catena Aurea · Matthäusevangelium 18
Woe unto the world because of offences! for it must needs be that offences come; but woe to that man by whom the offence cometh. Wherefore if thy hand or thy foot offend thee, cut them off, and cast them from thee: it is better for thee to enter into life halt or maimed, rather than having two hands or two feet to be cast into everlasting fire. And if thine eye offend thee, pluck it out, and cast it from thee: it is better for thee to enter into life with one eye, rather than having two eyes to be east into hell fire.
Or; The scandals that are to come are the Angels of Satan. But do not look that these offences should shew themselves in a substantial or natural shape, for in some the freedom of the will has been the origin of offence, not liking to undergo toil for virtue’s sake. But there cannot be real good, without the opposition of evil. It must needs be then that offences come, as it must needs be that we encounter the evil assaults of spiritual powers; whose hatred is the more stirred up, as Christ’s word invading men drives out the evil influences from them. And they seek instruments by whom the offences may the rather work;and to such instruments is more woe; for him who gives, it shall be worse than for him who takes, the offence, as it follows, But woe unto that man by whom the offence cometh.