法界次第初門 2.148

2.148

三、心念處者，六識能識諸塵，分別攀緣，謂之為心。是中觀內心智慧，名之為念。了知心從緣生，剎那不住，念念生滅，破常顛倒，即是處也。觀外心、內外心亦爾，是為心念處也。

Third, mindfulness of the mind: the six consciousnesses being able to cognize the various sense objects, discriminating and taking them as objects, is called the mind. Within this, the wisdom that contemplates the internal mind is called 'mindfulness'. Thoroughly knowing that the mind arises from conditions, does not abide for a moment, and arises and ceases moment by moment, to shatter the inversion of permanence, is 'basis'. Contemplating the external mind and internal-and-external mind is also like this. This is the mindfulness of the mind.