Nidānasutta

Suttapiṭaka · Saṁyuttanikāya · Nidānavaggasaṁyutta · Vol. 16 · Section 221

[221] Bhikkhus, suppose there were a great tree; whatever roots it has … . Even so, bhikkhus, when one dwells contemplating gratification (assāda) in things that fetter (saññojaniyā dhammā), there is a descent of consciousness. With consciousness as condition, name-and-form (nāmarūpa) … . Thus is the origin of this whole mass of suffering (dukkha).

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 1 other place

Vol. 16 · Section 207 — Paṭhammahārukkhasutta