Records the events that lead to the conversation of Upāli-Gahapati. The Buddha is asked, first by Dīghatapassī and then by Upāli, as to which of the three kinds of deeds — of body, speech, and mind — are the most blameworthy. Those of mind, says the Buddha; those of body, say the followers of Nāṭaputta. By various illustrations the Buddha convinces Upāli that his contentions are wrong. The sutta concludes with a series of verses (the Upāli Gāthā) in which Upāli sings the Buddha’s praises. M.i.371 ff.