The Tipiṭaka in Three Languages

Hetudukaajjhattāraṁmaṇattika

Abhidhammapiṭaka · Paṭṭhāna (5) · Vol. 44 · Section 862

[862] A phenomenon (dhamma) that is a root (hetu) and has an external object is a condition, by object condition (ārammaṇa-paccaya), for a phenomenon that is a root and has an external object: nine.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 5 other places