Aitareya Āraṇyaka 3.2.5

3.2.5

atha khalv iyaṃ sarvasyai vāca upaniṣat \
sarvā hy evemāḥ sarvasyai vāca upaniṣada.
imāṃ tv evācakṣate \
pṛthivyā rūpaṃ sparśā.
anta/rikṣasyoṣmāṇo.
divaḥ svarāḥ \
agne rūpaṃ sparśā.
vāyor ūṣmāṇa.
ādityasya svarāḥ \
ṛgvedasya rūpaṃ sparśā.
yajurvedasyoṣmāṇaḥ.
sāmavedasya svarāḥ \
cakṣuṣo rūpaṃ sparśāḥ.
śrotrasyoṣmāṇo.
manasaḥ svarāḥ \
prāṇasya rūpaṃ sparśā.
apānasyoṣmāṇo.
vyānasya svarāḥ \
atha khalv iyaṃ daivī vīṇā bhavati.
tadanukṛtir asau mānuṣī vīṇā bhavati \
yathāsyāḥ śira, evam amuṣyāḥ śiro.
yathāsyā udaram, eva/m amuṣyā ambhaṇaṃ.
yathāsyai jihvaivam amuṣyai vādanaṃ
yathāsyās tantraya, evam amuṣyā aṅgulayo.
yathāsyāḥ svarā, evam amuṣyāḥ svarā.
yathāsyā sparśā, evam amuṣyā sparśā.
yathā hy eveyaṃ śabdavatī tardmavaty, evam asau śabdavatī tardmavatī.
yathā hy eveyaṃ lomaśena carmaṇāpihitā bhava/ty, evam asau lomaśena carmaṇāpihitā \
lomaśena ha sma vai carmaṇā purā vīṇā apidadhati \
sa yo haitāṃ daivīṃ vīṇāṃ veda śrutavadano bhavati.
bhūmiprāsya kīrtir bhavati.
yatra kva cāryā vāco bhāṣante, vidur enaṃ tatra \
athāto vāgraso.
yasyāṃ saṃsady adhīyāno vā bhāṣamāṇo vā na viruruciṣeta, tatraitām ṛcaṃ japet \
oṣṭhā/pidhānā nakulī, dantaiḥ parivṛtā paviḥ \ sarvasyai vāca īśānā, cāru mām iha vādayet \
iti vāgrasaḥ \\ 5 \\

Now next the Upanishad of the whole speech.
True all these are Upanishads of the whole speech, but this they call so (chiefly).

The mute consonants represent the earth, the sibilants the sky, the vowels heaven.
The mute consonants represent Agni (fire), the sibilants air, the vowels the sun.
The mute consonants represent the Rig-veda, the sibilants the Yagur-veda, the vowels the Sâma-veda.
The mute consonants represent the eye, the sibilants the ear, the vowels the mind.
The mute consonants represent the up-breathing, the sibilants the down-breathing, the vowels the back-breathing.

Next comes this divine lute (the human body, made by the gods). The lute made by man is an imitation of it.

As there is a head of this, so there is a head of that (lute, made by man). As there is a stomach of this, so there is the cavity (In the board) of that. As there is a tongue of this, so there is a tongue in that. As there are fingers of this, so there are strings of that. As there are vowels of this, so there are tones of that. As there are consonants of this, so there are touches of that. As this is endowed with sound and firmly strung, so that is endowed with sound and firmly strung. As this is covered with a hairy skin, so that is covered with a hairy skin.

Verily, in former times they covered a lute with a hairy skin.

He who knows this lute made by the Devas (and meditates on it), is willingly listened to, his glory fills the earth, and wherever they speak Âryan languages, there they know him.

Next follows the verse, called vâgrasa, the essence of speech. When a man reciting or speaking in an assembly does not please, let him say this verse:

'May the queen of all speech, who is covered, as it were, by the lips, surrounded by teeth, as if by spears, who is a thunderbolt, help me to speak well.' This is the vâgrasa, the essence of speech.