[957] Bhikkhus, while a bhikkhu is dwelling diligent, ardent (ātāpī), and resolute, the pain faculty (dukkhindriya) arises in him. He understands thus: 'This pain faculty has arisen in me; and that has a sign (sanimitta), has a source, has a formation, has a condition. That a pain faculty could arise without a sign, without a source, without a formation, without a condition — this is impossible.' He understands the pain faculty, he understands the origin (samudaya) of the pain faculty, he understands the cessation (nirodha) of the pain faculty, and where the arisen pain faculty ceases without remainder — that too he understands.
And where does the arisen pain faculty cease without remainder? Here, bhikkhus, secluded from sensual pleasures, secluded from unwholesome states, a bhikkhu enters and dwells in the first jhāna, which is accompanied by thought and examination (savitakkaṃ savicāraṃ), with rapture (pīti) and pleasure born of seclusion. It is here that the arisen pain faculty ceases without remainder. This, bhikkhus, is called a bhikkhu who has understood the cessation of the pain faculty; he directs his mind (citta) toward that state.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.