大般涅槃經義記 3.143

3.143

下佛教中，「因《大涅槃》則易可知」總教驗法。「云何因」下別教驗法，先問、後辨，汎論驗法、驗說，必依三藏廣教能定是非。驗行必須加以四觀，共住、久處、智慧、觀察，是其四也，共住、久處驗其身行，智慧、觀察驗其心行。身有難知、易覺之別，其易覺者共住即知，共住不練加以久處。心中亦有難、易之別，其易識者慧驗即知，若慧不了加以觀察。准教驗心名為智慧，以理測尋說為觀察。

In the Buddha's instruction below, 'by means of the Mahānirvāṇa it is easy to know' generally instructs in the method of verification. From 'how by means of...' onward specifically instructs in the method of verification, first questioning and then explaining. Generally speaking, as for the method of verification, verifying doctrines must rely on the extensive teachings of the Three Baskets to determine right from wrong; verifying conduct must be augmented by the four observations: living together, dwelling for a long time, wisdom, and examination—these are the four. Living together and dwelling for a long time verify their physical conduct; wisdom and examination verify their mental conduct. The body has the distinction of being difficult to know or easy to perceive: that which is easy to perceive is known immediately upon living together; if living together does not make it clear, one adds dwelling for a long time. In the mind there is also the distinction between difficult and easy: that which is easy to recognize is known immediately upon verification through wisdom; if wisdom does not fully comprehend, one adds examination. Verifying the mind in accordance with the teaching is called 'wisdom'; searching and discerning according to principle is called 'examination.'