注維摩詰經 5.348

5.348

肇曰：係心於緣謂之止，分別深達謂之觀。止觀，助涅槃之要法。菩薩因之而行，不順之以墮涅槃也。

[Seng]zhao says: Binding the mind to an object is called calming; discerning and penetrating deeply is called insight. Calming and insight are the essential dharmas aiding nirvāṇa. The bodhisattva relies on them to practice, but does not comply with them so as to fall into nirvāṇa.