Dighanikaya 8.382

8.382

Ekaccaṃ tapassiṃ lūkhājīvintiādīsu idhekacco acelakapabbajjāditapanissitattā tapassī ‘‘lūkhena jīvitaṃ kappessāmī’’ti tiṇagomayādibhakkhanādīhi nānappakārehi attānaṃ kilameti, appapuññatāya ca sukhena jīvitavuttimeva na labhati, so tīṇi duccaritāni pūretvā niraye nibbattati.

Regarding 'a certain ascetic living a harsh life' and so forth: here, a certain ascetic, because of devotion to austerities such as the going forth of naked ascetics, thinking, 'I will maintain my life harshly,' torments himself in various ways through eating grass, cow dung, and so on, and due to having little merit he does not obtain even an easy means of living; having fulfilled the three kinds of misconduct, he is reborn in hell.