[156] Now at that time bhikkhus, having eaten fine foods, fell asleep with muddled mindfulness, not clearly comprehending. As they fell asleep with muddled mindfulness, not clearly comprehending, semen was emitted during a dream, and the lodging was soiled with the impurity. Then the Blessed One, walking on a tour of the lodgings with the Venerable Ānanda as his attendant ascetic (pacchāsamaṇa), saw a lodging soiled with impurity, and having seen it, he addressed the Venerable Ānanda: "Ānanda, with what is this lodging soiled?"
"At present, venerable sir, bhikkhus, having eaten fine foods, fall asleep with muddled mindfulness, not clearly comprehending. As they fall asleep with muddled mindfulness, not clearly comprehending, semen is emitted during a dream. That is why, Blessed One, this lodging is soiled with impurity."
"So it is, Ānanda; so it is, Ānanda. For, Ānanda, semen is emitted during a dream by those who fall asleep with muddled mindfulness, not clearly comprehending. Those bhikkhus, Ānanda, who fall asleep with mindfulness established and clearly comprehending—their semen is not emitted. Even those worldlings (puthujjana), Ānanda, who are free from lust for sensual pleasures—their semen is not emitted. It is impossible, Ānanda, there is no chance, that the semen of an arahant should be emitted."
Then the Blessed One, having given a Dhamma talk in that connection, on that account, addressed the bhikkhus: "Just now, bhikkhus, while walking on a tour of the lodgings with Ānanda as my attendant ascetic, I saw a lodging soiled with impurity, and having seen it, I asked Ānanda: 'Ānanda, with what is this lodging soiled?' 'At present, venerable sir, bhikkhus, having eaten fine foods, fall asleep with muddled mindfulness, not clearly comprehending. As they fall asleep with muddled mindfulness, not clearly comprehending, semen is emitted during a dream. That is why, Blessed One, this lodging is soiled with impurity.' 'So it is, Ānanda; so it is, Ānanda. For, Ānanda, semen is emitted during a dream by those who fall asleep with muddled mindfulness, not clearly comprehending. Those bhikkhus, Ānanda, who fall asleep with mindfulness established and clearly comprehending—their semen is not emitted. Even those worldlings, Ānanda, who are free from lust for sensual pleasures—their semen is not emitted. It is impossible, Ānanda, there is no chance, that the semen of an arahant should be emitted.'
"Bhikkhus, there are these five dangers for one who falls asleep with muddled mindfulness, not clearly comprehending: he sleeps in discomfort; he awakens in discomfort; he sees bad dreams; deities do not protect him; semen is emitted. These, bhikkhus, are the five dangers for one who falls asleep with muddled mindfulness, not clearly comprehending.
"Bhikkhus, there are these five benefits for one who falls asleep with mindfulness established, clearly comprehending: he sleeps at ease; he awakens at ease; he does not see bad dreams; deities protect him; semen is not emitted. These, bhikkhus, are the five benefits for one who falls asleep with mindfulness established, clearly comprehending.
"Bhikkhus, I allow a sitting cloth (nisīdana) for the protection of the body, for the protection of the robe, for the protection of the lodging."
Now at that time a sitting cloth, being too small, did not protect the whole lodging. They told this matter to the Blessed One. "Bhikkhus, I allow a sheet (paccattharaṇa) to be made as large as one wishes."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.