[41] Now at that time two bhikkhunīs were traveling on the highway road from Sāketa to Sāvatthī. Along the way a river had to be crossed. Then those bhikkhunīs approached the boatmen and said this: "Please, friends, ferry us across." "Noble ladies, it is not possible to ferry both across at once." One [boatman] ferried one [bhikkhunī] across. The one who had crossed violated the one who had crossed; the one who had not crossed violated the one who had not crossed. Afterwards, having met together, they asked one another: "I hope, noble lady, that you were not assaulted?" "I was assaulted, noble lady. But you, noble lady — were you not assaulted?" "I was assaulted, noble lady."
Then those bhikkhunīs, having gone to Sāvatthī, reported this matter to the bhikkhunīs. Those bhikkhunīs who were of few wishes … complained, criticized, and spread it about, saying: "How can a bhikkhunī go alone to the far shore of a river?" Then those bhikkhunīs reported this matter to the bhikkhus. The bhikkhus reported this matter to the Blessed One. … "Is it true, as they say, bhikkhus, that a bhikkhunī goes alone to the far shore of a river?" "It is true, Blessed One." The Buddha, the Blessed One, rebuked them: "How, bhikkhus, can a bhikkhunī go alone to the far shore of a river? This, bhikkhus, is not for the confidence of those without confidence … And thus, bhikkhus, let the bhikkhunīs recite this training rule:
'Whatever bhikkhunī should go alone among villages, or should go alone to the far shore of a river, this bhikkhunī too has committed a matter involving an offense at the very first act (paṭhamāpattika), a saṅghādisesa entailing sending away (nissāraṇīya).'"
And thus was this training rule laid down by the Blessed One for the bhikkhunīs.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.