大毘盧遮那成佛經疏 3.15

3.15

經云「復次祕密主！以響喻解了真言聲。如緣聲有響，彼真言者當如是解」者，《釋論》云「若深山峽谷中、若深絕㵎中、若空大舍中，以語言聲相擊故，從聲有聲名為響，無智人謂為有實。智者心念：『是聲無人作，但以聲轉故，更有響聲誑人耳根。』人欲語時，亦咽口中有風，名憂陀那，還入至齊。響出時，觸頂及齗齒脣舌咽胸七處而退，是名為語言。愚人不解而生三毒。智者了知心無所著，但隨諸法實相。」真言行者若於瑜伽中聞種種八風違順之音，或諸聖者以無量法音現前教授，或由舌根淨故能以一音遍滿世界，遇此諸境界時，亦當以響喻觀察，此但從三密眾緣而有，是事非生非滅、非有非無，是故於中不應妄生戲論，爾時自入音聲慧法門也。

The sūtra says: “Furthermore, Lord of Mysteries! Understand the sound of mantras through the simile of an echo. As an echo exists dependent upon sound, that mantrin should understand in this way.” The Expository Treatise says: “In deep mountain gorges, in deep and sheer ravines, or in vast empty halls, because vocal sounds reverberate against each other, sound arises from sound and is called an echo; unwise people consider it to be real. A wise person thinks: ‘This sound has no maker; it is merely that due to the propagation of sound, there is further an echo that deceives the ear faculty.’ When a person wishes to speak, there is also wind in the throat and mouth, called udāna, which returns down to the navel. When the sound comes forth, it strikes seven places—the crown of the head, gums, teeth, lips, tongue, throat, and chest—and then recedes; this is called speech. Deluded people do not understand and give rise to the three poisons. Wise people fully understand and their minds have no attachment, but merely accord with the dharmatā of all phenomena.” When a mantra practitioner, during yoga, hears the various sounds of the eight worldly winds, whether favorable or adverse, or when the holy ones manifest before them to instruct with immeasurable Dharma sounds, or when, through the purity of the tongue faculty, they are able to fill the worlds with a single sound—upon encountering all these states, they should also contemplate with the simile of an echo: these exist merely from the manifold conditions of the three mysteries; these matters neither arise nor cease, neither exist nor do not exist; therefore one should not falsely give rise to prapañca within them, and at that time will spontaneously enter the Dharma gateway of sound-wisdom.