A BRAHMANA IS HE WHO HAS NO INTIMACY WITH ANYONE
Asamsattham gahatthehi anagarehi c' ubhayam
Anokasarim appiccham tam aham brumi brahmanam.
He who is not intimate either with house-holders or with the homeless ones,
who wanders without an abode, who is without desires, - him I call a brahmana. 
Bhikkhu Tissa, after taking a subject of meditation, went to a mountain side. There, he found a cave which suited him and he spent the three months of the rainy season in that cave. He went to the village for almsfood every morning. In the village, there was a certain elderly woman who regularly offered him almsfood. In the cave there also lived a guardian spirit. As Tissa was one whose practice of morality was pure, she found it difficult to remain in the same cave as he was a noble monk. At the same time, she did not have the courage to ask him to leave the place. So she thought of a plan that would enable her to find fault with the monk and thus cause him to leave the cave.
The spirit decided to possess the youngest son of the woman to whose house Tissa usually went for his almsfood. She caused the boy to behave in a peculiar way, turning his head backwards, and rolling his wide open eyes. When the woman saw what had happened, she screamed and the spirit said, 'I have possessed your son. Let your monk wash his feet with water and sprinkle that water on the head of your son. Only then will I release your son.' The next day, when the monk came to her house for almsfood, she did what was demanded by the spirit and the boy was left in peace. The spirit went back to the cave and waited at the entrance for the monk. When Tissa returned, she revealed herself and said, 'I am the spirit guarding this cave, O you exorcist, don't enter this cave.' The monk knew that he had lived a virtuous life from the day he had become a monk, so he replied that he had not broken the precept of abstaining from practising exorcism or witchcraft. Then she accused Tissa of having treated the young boy possessed by a spirit at the house of the elderly woman. But the monk reflected that he had not practised exorcism and realised that even the spirit could find no fault with him. That gave him a delightful satisfaction and happiness; he attained Arahanthood while standing at the entrance to the cave.
Since Tissa had now become an Arahant, he told the spirit that she had wrongly accused a monk like him whose virtue was pure and spotless and also advised her not to cause further disturbances. Tissa continued to stay in the cave till the end of thevassa, and then he returned to the Jetavana monastery. When he told the other bhikkhus about his encounter with the spirit, they asked him whether he had been angry with the spirit when he was forbidden to enter the cave. He answered in the negative. The other bhikkhus asked the Buddha, 'Venerable Tissa claims he has no more anger. Is it true?' The Buddha replied, 'Bhikkhus, Tissa is speaking the truth. He has indeed become an Arahant; he is no longer attached to anyone; he has no reason to get angry with anyone.'