Apophthegmata Patrum. Chapter 10. About discretion.
One brother lived in silence, and the demons in the form of angels sought to seduce him on a pretext of a brethren’s meeting for prayer. They arouse him, ask him and show him some sign of light. He then went to one elder and told him: Abba, angels come to me with light and wake me up to join the brethren for our common prayer. And the elder says to him: ‘Don’t listen to them, my child! They are demons; but when they come to wake you, tell him I will stand up only when I want and I won’t listen to you.’ The brother, having accepted the elder’s instruction, went to his cell. The next night again demons came and woke him up again. He answered them, as the elder commanded him to answer, saying: I would stand up when I wanted, and I would not listen to you. The demons told him: ‘This evil elder was a liar, he deceived you. For his brother came to him, wanting to borrow money, and he, having the money, told him a lie, saying: “I have no money” - and did not give him. From this, understand that he is a liar.’ Brother got up, went to the elder and told him about it. The elder told him: ‘You are right, I had money, and when my brother came and asked me, I did not give it, because I knew that if I gave it to him, it would be bad for his soul. So I decided to break one commandment instead of ten so we wouldn’t grieve. Do not listen to the demons who seek to deceive you.’ And this brother, much confirmed by the elder, went to his cell.