The Tipiṭaka in Three Languages

Hetudukaparittattika

Abhidhammapiṭaka · Paṭṭhāna (5) · Vol. 44 · Section 543

[543] A limited phenomenon (dhamma) that is a root (hetu) is a condition, by root condition (hetu-paccaya), for a limited phenomenon that is a root: three.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 5 other places