योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-63, verse-2

श्रीवसिष्ठ उवाच ।
वर्णेषु खशरीराणां वर्णाः कचटतादयः ।
कदाचनापि नोद्यन्ति शवानामिव केन च ॥ २ ॥

śrīvasiṣṭha uvāca ,
varṇeṣu khaśarīrāṇāṃ varṇāḥ kacaṭatādayaḥ ,
kadācanāpi nodyanti śavānāmiva kena ca 2

2. Vasishtha replied:—The incorporeal or vacuous bodies, have of course no power or capability of pronouncing the articulate letters of the alphabet; just as dead bodies incapable of speech.