"'So, friends, it seems that you don't know that you existed in the past, and that you did not not exist; you don't know that you did evil actions in the past, and that you did not not do them; you don't know that you did such-and-such evil actions in the past; you don't know that so-and-so much stress has been exhausted, or that so-and-so much stress remains to be exhausted, or that with the exhaustion of so-and-so much stress all stress will be exhausted; you don't know what is the abandoning of unskillful mental qualities and the attainment of skillful mental qualities in the here-&-now. That being the case, those in the world who are murderers, bloody-handed doers of what is cruel, when they are later reborn among human beings, go forth with the Niganthas.'
Who are Niganthas:
"Once, Mahanama, when I was staying near Rajagaha on Vulture Peak Mountain, a number of Niganthas were at Black Rock on the slopes of Isigili, practicing continuous standing: rejecting seats, experiencing fierce, sharp, racking pains due to exertion. So in the evening, rising from seclusion, I went to the Niganthas at Black Rock on the slopes of Isigili and on arrival asked them, 'Why are you practicing continuous standing: rejecting seats, experiencing fierce, sharp, racking pains due to exertion?' When this was said, the Niganthas said to me, 'Friend, the Nigantha Nataputta[5] is all-knowing, all-seeing, and claims total knowledge & vision thus: "Whether I am walking or standing, sleeping or awake, knowledge & vision are continuously & continually established in me." He has told us, "Niganthas, there are evil actions that you have done in the past. Exhaust them with these painful austerities. When in the present you are restrained in body, restrained in speech, and restrained in mind, that is the non-doing of evil action for the future. Thus, with the destruction of old actions through asceticism, and with the non-doing of new actions, there will be no flow into the future. With no flow into the future, there is the ending of action. With the ending of action, the ending of stress. With the ending of stress, the ending of feeling. With the ending of feeling, all suffering & stress will be exhausted."[6] We approve of that [teaching], prefer it, and are gratified by it.'