《旧唐书·列传·卷一百四十一》
当初，弘忍和道信一起住在东山寺，所以称他的佛法为东山佛门。
初，弘忍与道信并住东山寺，故谓其法为东山法门。
In the earlier time, Hongren and Daoxin lived in the temple of Dongshan together, therefore, his Buddhism was named after the Dongshan Religion.