[70] Now at that time a certain bhikkhu, having gone for his daytime abiding (divāvihāra) at the hall with the peaked roof in the Great Wood at Vesālī, was lying down having left the door open. His limbs were stiffened with wind. Now at that time a number of women, taking perfumes and garlands, came to the monastery to look at the dwellings. Then those women, seeing that bhikkhu, sat down upon his member, and having done as much as they wished, saying, "What a bull of a man this is!" they placed the perfumes and garlands upon him and departed. The bhikkhu, seeing the soiled state, reported this matter to the Blessed One.¹ "Bhikkhus, in five ways the member becomes erect (kammaniya): through lust, through [the pressure of] excrement, through [the pressure of] urine, through wind, and through the bite of a hairy caterpillar. In these five ways, bhikkhus, the member becomes erect. It is impossible, bhikkhus, there is no chance, that that bhikkhu's member should have become erect through lust; that bhikkhu, bhikkhus, is an arahant. There is no offence, bhikkhus, for that bhikkhu. I allow, bhikkhus, one who goes into seclusion during the day to go into seclusion having closed the door."
¹ [Editorial footnote, Siam Raṭṭha ed.:] Here too, in the aforementioned printed books, the construction is made in the plural.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.