One night the Deceiver instilled dastardly thoughts in his heart and, then, when the darkness was profound, (the unclean spirit) brought forth the vision of a Saracen with drawn sword, who threatened to cut off Theognius’ head on the spot, if he would not come immediately out of his cave. Thus the man leant out of the cave, full of fear and prayed God to do with him whatever was best. And an angel appeared to him at once and said to him in a very harsh voice: “You look a wretched coward to me: go back into your cave and fear nothing at all. For this is no Saracen as you think, but it is an unclean spirit that has turned itself into the shape of a Saracen.” So the terror left him at once. (Theognius) was filled with courage and ineffable joy and the demon took himself away. Then, as the wonderful man became famous, some Christ-loving men, came to him, and after strenuous entreaties, finally persuaded him to build a small tower - which was done. Although many desired to join him, Theognius absolutely refused to mix with a crowd, but accepted only a few men and lived with them in fear of God, performing the divine services as is customary for ascetes.
(transl. Leah Di Segni)