[452] Now at that time several bhikkhus and bhikkhunīs were traveling along the highroad from Sāketa to Sāvatthī. Then those bhikkhunīs, seeing those bhikkhus, said this: "We too will go along with the noble sirs."
"Sisters, it is not proper to travel by arrangement together with a bhikkhunī on the same highroad. Either you go first, or we will go."
"Venerable sirs, the noble sirs are the foremost of men; let the noble sirs themselves go first."
Then, as those bhikkhunīs were going along afterwards, robbers on the way both robbed and violated them. Then those bhikkhunīs, having gone to Sāvatthī, told this matter to the bhikkhunīs. The bhikkhunīs told this matter to the bhikkhus. The bhikkhus told this matter to the Blessed One.
Then the Blessed One, having given a talk on the Dhamma in that connection, on that occasion, addressed the bhikkhus: "Bhikkhus, when a road is to be traveled with a caravan, is agreed to be risky, and is fraught with danger, I allow one to travel by arrangement together with a bhikkhunī on the same highroad. And thus, bhikkhus, you should recite this training rule:
"Whatever bhikkhu should travel by arrangement together with a bhikkhunī on the same highroad, even for the interval between one village and the next, except at a proper occasion, there is an offense of pācittiya. Herein this is the proper occasion: the road is to be traveled with a caravan, is agreed to be risky, and is fraught with danger — this is the proper occasion in this case."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.