佛祖統紀 3.34

3.34

言八教者。頓漸祕密不定為化儀。藏通別圓為化法。是為八教。化儀如世藥方。化法如辨藥味。

Regarding the eight teachings: sudden, gradual, secret, and indeterminate are the converting methods; tripiṭaka, common, separate, and perfect are the converting doctrines. These are the eight teachings. The converting methods are like worldly medical prescriptions; the converting doctrines are like distinguishing medicinal flavours.