[19] Sitting to one side, Dasama the householder, a citizen of Aṭṭhakanagara, said to the Venerable Ānanda: "Venerable Ānanda, is there one thing (ekadhamma) declared by that Blessed One who knows and sees, the Arahant, the Fully Self-Enlightened One, wherein, for a bhikkhu dwelling diligent, ardent (ātāpī), and resolute, the mind (citta) not yet liberated comes to be liberated, the taints (āsava) not yet exhausted come to exhaustion, and he attains the unsurpassed security from bondage (yogakkhema) not yet attained?"
"There is, householder, one thing declared by that Blessed One who knows and sees, the Arahant, the Fully Self-Enlightened One, wherein, for a bhikkhu dwelling diligent, ardent, and resolute, the mind not yet liberated comes to be liberated, the taints not yet exhausted come to exhaustion, and he attains the unsurpassed security from bondage not yet attained."
"But what, Venerable Ānanda, is the one thing declared by that Blessed One who knows and sees, the Arahant, the Fully Self-Enlightened One, wherein, for a bhikkhu dwelling diligent, ardent, and resolute, the mind not yet liberated comes to be liberated, the taints not yet exhausted come to exhaustion, and he attains the unsurpassed security from bondage not yet attained?"
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.