[329] Now at that time those bhikkhus departed from that dwelling. The bhikkhunīs, thinking, "The venerable ones have departed," did not come to the monastery (ārāma). Then those bhikkhus returned once again to that dwelling. The bhikkhunīs, thinking, "The venerable ones have returned," asked leave, entered the monastery, and approached those bhikkhus; having approached and paid homage to those bhikkhus, they stood to one side. When those bhikkhunīs had stood to one side, those bhikkhus said this to them: "Sisters, why did you neither sweep the monastery nor set out drinking water and water for use?"
"Venerable sirs, a training rule (sikkhāpada) has been laid down by the Blessed One: 'The monastery is not to be entered without asking leave.' Therefore we did not come."
They reported this matter to the Blessed One. "Bhikkhus, I allow [a bhikkhunī] to enter a monastery after asking leave of a bhikkhu who is present. And thus, bhikkhus, let the bhikkhunīs recite this training rule: 'Whatever bhikkhunī should enter a monastery without asking leave of a bhikkhu who is present, there is an offense of expiation (pācittiya).'"
[Editorial notes in the Siam Raṭṭha edition: (1) In the Burmese and European editions the vocative "bhikkhave" appears here; (2) the word "hoti" appears (i.e., "a training rule has been laid down").]
And thus this training rule was laid down by the Blessed One for the bhikkhunīs.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.