[610] At that time the Blessed One, the Buddha, was dwelling at Rājagaha, in the Veḷuvana, the squirrels' feeding ground. Now at that time bhikkhus were bathing in the Tapodā (hot springs). Then King Seniya Bimbisāra of Magadha, thinking, "I shall bathe my head," went to the Tapodā and waited to one side, thinking, "I shall wait until the venerable ones have finished bathing." The bhikkhus bathed until it was quite dark. Then King Seniya Bimbisāra of Magadha, having bathed his head at the wrong time, and the city gate being shut, spent the night outside the city; and early in the morning, with his unguents still fresh, he approached the Blessed One; having approached and paid homage to the Blessed One, he sat down to one side. As King Seniya Bimbisāra of Magadha sat to one side, the Blessed One said this to him: "Why, great king, have you come so early in the morning, with your unguents still fresh?" Then King Seniya Bimbisāra of Magadha reported the matter to the Blessed One. Then the Blessed One instructed, roused, inspired, and gladdened King Seniya Bimbisāra of Magadha with a talk on the Dhamma. Then King Seniya Bimbisāra of Magadha, having been instructed, roused, inspired, and gladdened by the Blessed One with a talk on the Dhamma, rose from his seat, paid homage to the Blessed One, circumambulated him keeping his right side toward him, and departed.
Then the Blessed One, on this occasion, in this connection, had the community of bhikkhus assembled and questioned the bhikkhus: "Is it true, bhikkhus, as is said, that bhikkhus, even having seen the king, went on bathing without knowing moderation?"
"It is true, Blessed One."
The Buddha, the Blessed One, rebuked them: "How, bhikkhus, can these foolish men, even having seen the king, go on bathing without knowing moderation? This, bhikkhus, is not for the confidence of those without confidence, nor for the increase of confidence in those who have it …
"And thus, bhikkhus, you should recite this training rule (sikkhāpada): 'Should any bhikkhu bathe at intervals of less than half a month, there is an offense of pācittiya.'"
And thus this training rule was laid down by the Blessed One for the bhikkhus.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.