[523] Sāvatthī. Sitting to one side, that bhikkhu said this to the Blessed One: "Venerable sir, what is the cause, what is the condition, why some spontaneously born nāgas here observe the uposatha and relinquish their bodies?"
"Here, bhikkhu, it occurs to some spontaneously born nāgas thus: 'Formerly we were doers of deeds of both kinds (dvayakārino) by body, doers of deeds of both kinds by speech, doers of deeds of both kinds by mind. Having been doers of deeds of both kinds by body, doers of deeds of both kinds by speech, doers of deeds of both kinds by mind, with the breaking up of the body, after death, we were reborn in companionship with the spontaneously born nāgas. If today we were to practice good conduct by body, practice good conduct by speech, practice good conduct by mind, then with the breaking up of the body, after death, we would be reborn in a good destination, in a heavenly world. Come now, let us at this very time practice good conduct by body, practice good conduct by speech, practice good conduct by mind.' This, bhikkhu, is the cause, this is the condition why some spontaneously born nāgas here observe the uposatha and relinquish their bodies."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.