A certain brother was engaged in a war against Satan, and he told the matter to Abba Herakles and wishing to strengthen and confirm him the old man told him the following story, “There was a certain old man who had a disciple, and he had been very obedient to him for many years, and when the war came upon him, he made a request to his master, saying, ‘I beseech you to make me a monk.’ The master said to him, ‘Seek out a place for yourself, and we will build a cell for you, and you shall become a monk.’ The disciple went and found a place, which was distant from his master about one hundred paces, and he made himself a cell. Then the old man said to that brother, ‘Whatever I say to you, that do. When you are hungry, eat and when you are thirsty, drink and sleep, but you must not go out from your cell until the Sabbath Day, when you shall come to me.’ Then the old man went back to his cell. The brother did according to what the old man told him for two days, but on the third day he became dejected, wearied, and he said, ‘What has the old man done for me, seeing that he has not commanded me to make prayers?’ Then he rose up and sang more Psalms than usual. After the sun had set he ate his food, he rose up, went, laid down upon his mat and he saw, as it were, an Ethiopian who stood up and gnashed his teeth at him. The monk, by reason of his great fear, ran quickly to his master, and he knocked hastily at his door, saying, ‘Father, have mercy upon me, and open to me immediately.’ Now because the old man knew that he had not kept his commandment he refused to open the door to him until the morning. When he opened the door in the morning, he found him there, and as the brother entreated him to be allowed to enter, the old man had compassion upon him and brought him in. Then he began to say to the old man, ‘I beseech you, O father, to believe me. When I went to lie down to go to sleep, I saw a black Ethiopian on my bed.’ The old man said to him, ‘This happened because you did not keep my words.’ Then he laid down a rule for him which was suitable to his strength and to the monastic life, and dismissed him, and little by little he became an excellent monk.