MahāvaggavaggaParihānikathā

Abhidhammapiṭaka · Kathāvatthu · Vol. 37 · Section 203

[203] "Does the Non-Returner (anāgāmī) fall away from the fruition of Non-Returning (anāgāmi-phala)?" "Yes." "Does the Stream-Enterer (sotāpanna) fall away from the fruition of Stream-Entry (sotāpatti-phala)?" "It should not be said thus." "By whom have more defilements (kilesā) been abandoned — by the Non-Returner or by the Stream-Enterer?" "By the Non-Returner." "If by the Non-Returner more defilements have been abandoned, and the Non-Returner falls away from the fruition of Non-Returning, then indeed, good sir, it should be said: 'The Stream-Enterer falls away from the fruition of Stream-Entry.'"

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 2 other places