[451] At that time the Buddha, the Blessed One, was dwelling at Sāvatthī, in the Jeta Grove, in Anāthapiṇḍika's park. Now at that time the group-of-six bhikkhus (chabbaggiyā bhikkhū), having made an arrangement, set out on the same road together with bhikkhunīs. People criticized, complained, and spread it about, saying: "Just as we go wandering about together with our wives, so too do these ascetics, sons of the Sakyan, go wandering about together with bhikkhunīs." Bhikkhus heard those people criticizing, complaining, and spreading it about. Those bhikkhus who were of few wishes … criticized, complained, and spread it about: "How can the group-of-six bhikkhus, having made an arrangement, set out on the same road together with bhikkhunīs?" … "Is it true, as is said, bhikkhus, that you, having made an arrangement, set out on the same road together with bhikkhunīs?"
"It is true, Blessed One."
The Buddha, the Blessed One, rebuked them: "How can you, foolish men, having made an arrangement, set out on the same road together with bhikkhunīs? This, foolish men, is not for the confidence of those without confidence … And thus, bhikkhus, you should recite this training rule (sikkhāpada):
"Whatever bhikkhu should, having made an arrangement with a bhikkhunī, set out on the same road, even so much as the interval between villages, 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English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.