弘明集 8.42

8.42

三破論云。佛舊經本云。浮屠羅什改為佛徒。知其源惡故也。所以詺為浮屠。胡人凶惡故。老子云。化其始不欲傷其形。故髠其頭名為浮屠。況屠割也。至僧禕後改為佛圖。本舊經云。喪門喪門由死滅之門。云其法無生之教。名曰喪門。至羅什又改為桑門。僧禕又改為沙門。沙門由沙汰之法。不足可稱。

The Treatise on the Three Destructions says: "The old versions of Buddhist scriptures originally said futu; Kumārajīva altered it to fotu ('follower of the Buddha') because he recognized the evil of its origin. The reason it was called futu was that the barbarians were fierce and wicked. Laozi said that when he began converting them, he did not wish to harm their bodies, and therefore shaved their heads and named them futu, likening it to butchering (tu). Coming down to Sengyi, it was later altered to fotu ('image of the Buddha'). Originally, old scriptures said sangmen ('gate of mourning'); 'gate of mourning' came from the gate of death and extinction, meaning that its Dharma was a teaching of non-birth, hence called sangmen. Coming down to Kumārajīva, he changed it again to sangmen ('mulberry gate'); Sengyi again changed it to shamen (śramaṇa). Shamen comes from the method of sorting (shatai); it is not worth praising."