The Tipiṭaka in Three Languages

Ṭhāniyasutta

Suttapiṭaka · Saṁyuttanikāya · Mahāvaggasaṁyutta · Vol. 19 · Section 440

[440] Bhikkhus, through frequent application of attention (manasikāra) to things that are a basis for dullness and drowsiness (thīna-middha), unarisen dullness and drowsiness arises, and arisen dullness and drowsiness leads to increase and expansion.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 3 other places