大乘起信論義記 1.103

1.103

前中，初、約勝時以明根勝。二、能說人下，明緣勝。於中三業可知。一音及圓音者，有二：初、如來一音說一切法，無不顯了，故名圓音。《華嚴》云「如來於一語言中演說無邊契經海。」二、如來同一切音，故云圓音。《華嚴》云「一切眾生語言法，一言演說盡無餘。」以一切音即一音，故云一音。一音即一切音，故云圓音。一一語音遍窮眾生界，而其音韻恒不雜亂。若音不遍，則音非圓；若由等遍失其韻曲，則是圓非音。今不壞曲而等遍，不動遍而善韻，此是如來圓音，非是心識思量境界耳。

In the former: first, it clarifies the superiority of faculties in terms of the superior time; second, from "the speaker" onward, it clarifies the superiority of conditions. Within this, the three karmas can be understood. Regarding the single sound and the round sound, there are two explanations: First, the Tathāgata proclaims all dharmas with a single sound, leaving nothing unrevealed; hence it is called the round sound. The *Avataṃsaka* says: "The Tathāgata, within a single verbal expression, expounds an ocean of boundless sūtras." Second, the Tathāgata is identical with all sounds; hence it is called the round sound. The *Avataṃsaka* says: "The Dharma of all sentient beings' spoken languages, in a single word, he expounds without remainder." Because all sounds are precisely the single sound, it is called the single sound; because the single sound is precisely all sounds, it is called the round sound. Each and every vocal sound pervades sentient realms to their ends, yet their phonetics and tones are never jumbled. If the sound were not all-pervasive, the sound would not be round; if by being equally all-pervasive it lost its musical pitch, it would be round but not a sound. Now, without destroying the tune it is equally all-pervasive, and without moving from pervasiveness it has exquisite melody; this is the round sound of the Tathāgata, not a sphere of conceptual measurement by the conscious mind.