Śrīmad-Bhāgavatam · Texts 12.6.40-41
Who is speaking and story frame
शृणोति य इमं स्फोटं सुप्तश्रोत्रे च शून्यदृक् ।
येन वाग् व्यज्यते यस्य व्यक्तिराकाश आत्मन: ॥ ४० ॥
स्वधाम्नो ब्राह्मण: साक्षाद् वाचक: परमात्मन: ।
स सर्वमन्त्रोपनिषद्वेदबीजं सनातनम् ॥ ४१ ॥
śṛṇoti ya imaṁ sphoṭaṁ
supta-śrotre ca śūnya-dṛk
yena vāg vyajyate yasya
vyaktir ākāśa ātmanaḥ
sva-dhāmno brahmaṇaḥ sākṣād
vācakaḥ paramātmanaḥ
sa sarva-mantropaniṣad
veda-bījaṁ sanātanam
This oṁkāra, ultimately nonmaterial and imperceptible, is heard by the Supersoul without His possessing material ears or any other material senses. The entire expanse of Vedic sound is elaborated from oṁkāra, which appears from the soul, within the sky of the heart. It is the direct designation of the self-originating Absolute Truth, the Supersoul, and is the secret essence and eternal seed of all Vedic hymns.
Read the purport on Vedabase.ioFrom Canto 10, chapter 14 onward, the translation and purports were completed by Śrīla Prabhupāda's disciples after his departure, and published by the Bhaktivedanta Book Trust.