因明入正理論疏 2.85

2.85

略為三者：謂自性、變易、我知者。自性者，古云冥性，未成大等名自性，將成大等亦名勝性，勝異舊故。變易者，謂中間二十三諦，非體新生，根本自性所轉變故。我知者，謂神我，能受用境，有妙用故。

The brief division into three refers to: primordial nature (prakṛti), transformation (vikāra), and the knower-self (jña/puruṣa). Primordial nature: anciently called 'obscure nature' (míngxìng). Before producing the great principle (mahat) and the rest, it is called primordial nature; when about to produce the great principle and the rest, it is also called superior nature (pradhāna), because it surpasses and differs from the former. Transformation refers to the intermediate twenty-three principles; they are not newly born substances, but transformations of the fundamental primordial nature. The knower-self refers to the spiritual self (puruṣa); because it can experience objects, it possesses wondrous function.