摩訶止觀 4.75

4.75

若不解此十心，全不識是非，云何懺悔？設入道場，徒為苦行，終無大益。《涅槃》云：「若言勤修苦行是大涅槃近因緣者，無有是處。」即此意也。是名懺悔事中重罪也。

If one does not understand these ten mindsets and does not recognize right and wrong at all, how can one repent? Even if one enters the bodhimaṇḍa, it is mere futile asceticism and ultimately of no great benefit. The Nirvāṇa [Sūtra] says: 'If one says that diligently cultivating asceticism is a proximate cause and condition of great nirvāṇa, there is no such thing.' This is precisely its meaning. This is called repenting of grave transgressions in the realm of phenomena.