大乘百法明門論開宗義決 1.221

1.221

說正思惟是無漏者。顯揚瑜伽二論皆說　思惟諸諦得與無漏作意相應。此中思惟即是尋求。既許尋求是無漏。故伺通無漏其義准知。

"Stating that right thought is uncontaminated": both the *Prakaraṇāryavācā* and the *Yogācārabhūmi* state that thinking upon the truths can be associated with uncontaminated mental engagement. Here, 'thinking' is precisely investigation (vitarka). Since it is accepted that investigation is uncontaminated, it should be inferred accordingly that analysis also extends to being uncontaminated.