[149] Then, while the Blessed One was alone in seclusion, this reflection arose in his mind: "What if I were to allow those training rules (sikkhāpada) which I have laid down for the bhikkhus to be recited as the Pātimokkha recitation (pātimokkhuddesa) for them? That will be their Uposatha observance (uposathakamma)." Then in the evening, the Blessed One, having emerged from seclusion, having given a Dhamma talk with reference to that occasion, with reference to that incident, addressed the bhikkhus: "Bhikkhus, while I was alone in seclusion here, this reflection arose in my mind: 'What if I were to allow those training rules which I have laid down for the bhikkhus to be recited as the Pātimokkha recitation for them? That will be their Uposatha observance.' Bhikkhus, I allow the Pātimokkha to be recited.
"And thus, bhikkhus, should it be recited: the Saṅgha should be informed by a competent and capable bhikkhu: 'Venerable sirs, let the Saṅgha hear me.¹ If the Saṅgha is ready, let the Saṅgha perform the Uposatha, let it recite the Pātimokkha. What is the preliminary duty of the Saṅgha? Let the venerable ones announce their purity (pārisuddhi). I shall recite the Pātimokkha. Let all of us who are present listen to it carefully and attend to it. Whoever has an offence (āpatti) should reveal it; when there is no offence, one should remain silent. By their silence I shall know of the venerable ones: "They are pure." And just as there is an answer for one who is questioned individually, even so in an assembly such as this it is proclaimed up to the third time. Whatever bhikkhu, while it is being proclaimed up to the third time, remembering an existing offence, should not reveal it, incurs deliberate false speech (sampajānamusāvāda). Now deliberate false speech, venerable ones, has been declared by the Blessed One to be an obstructive thing. Therefore a bhikkhu who has committed an offence, who remembers it and desires purification, should reveal the existing offence; for when it has been revealed, there is ease for him.'"
¹ [Siam Raṭṭha editorial footnote:] From this point onward, in all books except the Sinhalese book, the reading "ajj'uposatho paṇṇaraso" ("Today is the Uposatha, the fifteenth") appears. But since at this point the day has not yet been allowed — for it will be said below, "Now at that time the bhikkhus, [thinking] 'The Pātimokkha recitation has been allowed by the Blessed One,' recited the Pātimokkha daily," and so forth — if the day had been allowed here, those bhikkhus would not have recited it daily; therefore it is not fitting here, though it is proper from the time the day was allowed onward. It should be understood that this passage has been emended in accordance with the Sinhalese book.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.