成唯識論述記 2.931

2.931

述曰：下自解也，即心空理真如是心，心性淨者，真實性故，《勝鬘經》中具說此義。其《對法論》第十卷，三轉依中，解心轉依真如，說為心本性淨，以起煩惱覆此淨心。今斷染惑證淨心性故。

The Commentary states: Below is the [treatise's] own explanation: tathatā, the principle of emptiness of the mind, is the mind, and the purity of the mind's nature is because it is the true nature; the Śrīmālādevī-sūtra explains this meaning in full. The tenth fascicle of the Abhidharmasamuccaya-bhāṣya, under the three transformations of the basis, explains the transformation of the basis of the mind as tathatā, calling it the fundamentally pure nature of the mind, because arisen defilements veil this pure mind, and now by severing defilements and delusions one realizes the pure nature of mind.