金剛經纂要刊定記 2.81

2.81

或曰：「諸家所出教體，皆取聲、名、句、文，或通取所詮之法，今何單取文字耶？」由是疏云：「文字即含聲、名、句、文」，此明具四法也。聲即言音。名、句、文三，即聲上屈曲表示，名詮諸法自性，句詮諸法差別，文即是字，為二所依也。

Someone asked: "When the various masters set forth the substance of the teaching, they all take sounds, names, phrases, and phonemes, or comprehensively take the phenomena that are signified; why do you now take literary [prajñā] alone?" For this reason, the commentary says: "Literary [prajñā] contains sounds, names, phrases, and phonemes," which clarifies that it possesses the four phenomena. "Sound" is speech and voice. The three—names, phrases, and phonemes—are variations and expressions upon sound: names express the self-nature of phenomena, phrases express the distinctions among phenomena, and phonemes are characters/letters, which serve as the support for the two.