佛祖歷代通載 10.6

10.6

真觀法師釋門龍象也。時徐僕射領軍禦世。欲僧兵之。師馳書勉止。其言傷怛足以發回向之心。又著無性因緣論。

Dharma Master Zhenguan was a dragon and elephant in the gate of Śākya. At that time, Vice Director Xu commanded the army to govern the state and wished to conscript monks into the army. The master sent a letter swiftly to exhort him to stop; his words were sorrowful and poignant, sufficient to arouse a mind of turning toward [the Dharma]. He also wrote the Treatise on Causes and Conditions of Non-Nature (Wuxing yinyuan lun).