Upakkilesasutta

Suttapiṭaka · Majjhimanikāya · Vol. 14 · Section 454

[454] And so I, Anuruddha, … . Then, Anuruddha, it occurred to me: 'Dullness and drowsiness (thīna-middha) has arisen in me; and on account of dullness and drowsiness my concentration (samādhi) fell away. When concentration falls away, the light and the vision of forms disappear. I shall so act that doubt (vicikicchā) will not arise in me again, nor inattention, nor dullness and drowsiness.'

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.