[186] "There are, Sāriputta, some ascetics and brahmins who hold this doctrine and this view: 'Purity comes about through food.' They say: 'We subsist on mung beans' … 'We subsist on sesame' … 'We subsist on rice grains.' They eat rice grains, they eat rice-grain powder, they drink rice-grain water, and they consume many kinds of preparations of rice grains. But I recall, Sāriputta, having taken just a single rice grain as food. It may be, Sāriputta, that you think: 'Surely the rice grain must have been large at that time.' But it should not be seen thus, Sāriputta: even then the rice grain was at most that very size, just as it is now. As I took just a single rice grain as food, Sāriputta, my body reached a state of extreme emaciation. Because of that very scantiness of food, my limbs great and small became just like the jointed segments of the āsītika creeper or the kāḷa creeper. Just as a camel's hoofprint … because of that very scantiness of food. Just as a string of beads … because of that very scantiness of food. Just as of an old hall … Just as in a deep … Just as a bitter gourd … And I, Sāriputta, the skin of my belly … And I, Sāriputta, excrement or … And I, Sāriputta, that very body … fell from my body, because of that very scantiness of food.
Yet, Sāriputta, even by that conduct, by that practice, by that performance of what is so hard to do, I did not attain any distinction of knowledge (ñāṇa) and vision worthy of the noble ones, surpassing the human state. Why was that? Because of the non-attainment of this very noble wisdom — that noble wisdom which, when attained, is noble and emancipating, and leads the one who acts accordingly to the complete destruction of suffering (dukkha)."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.