摩訶止觀 3.39

3.39

教相顯者，夫止觀名教，通於凡聖；不可尋通名，求於別體，故用相簡之。

As for revealing through doctrinal characteristics: the names and teachings of calming and contemplation apply generally across ordinary beings and sages; one must not pursue a common name to seek a distinctive substance, and so we use characteristics to distinguish it.