妙法蓮華經玄義 9.128

9.128

△大章第四、明用者，用是如來之妙能，此經之勝用。如來以權實二智為妙能，此經以斷疑生信為勝用，秖二智能斷疑生信，生信斷疑由於二智，約人約法左右互論耳。

Major Section Four: Clarifying the Function. 'Function' is the wondrous capability of the Tathāgata and the superior function of this sūtra. The Tathāgata takes the two wisdoms—provisional and real—as his wondrous capability; this sūtra takes the severing of doubt and the generating of faith as its superior function. It is solely the two wisdoms that can sever doubt and generate faith; the generating of faith and the severing of doubt depend on the two wisdoms. In terms of person and in terms of dharma, they are discussed reciprocally.