摩訶止觀 7.36

7.36

皆是無漏者，即是見諦思惟所行道品，一向是無漏。《法華》之文意在此也。從來雖言有漏中得修八正、七覺等，未有文證。

That they are all undefiled means that the factors of the path practiced upon seeing the truths and contemplating them are consistently undefiled. The intention of the Lotus Sūtra's text lies here. Although it has always been said that one can cultivate the eight noble [factors], the seven limbs of awakening, and so forth in the defiled state, there has not been textual evidence for it.