Aitareya Āraṇyaka 3.1.2

3.1.2

atha śākalyasya \
pṛthivī pūrvarūpaṃ.
dyaur uttararūpaṃ.
vṛṣṭiḥ saṃdhiḥ.
parjanyaḥ saṃdhātā \
tad utāpi yatraitad valavad anudgṛhṇan saṃdadhad ahorātre varṣati, dyāvāpṛthivyau samadhātām ity utāpy āhuḥ \
itī nv adhidai/vatam \
athādhyātmam \
puruṣo ha vā ayaṃ sarva āndaṃ.
dve bidale bhavata ity āhus.
tasyedam eva pṛthivyā rūpam, idaṃ divas.
tatrāyam antare/ṇākāśo, yathāsau dyāvāpṛthivyāv antareṇākāśaḥ \
tasmin hāsmi/nn ākāśe prāṇa āyatto, yathāmuṣminn ākāśe vāyur āyattaḥ \
yathā/mūni trīṇi jyotīṃṣy, evam imāni puruṣe trīṇi jyotīṃṣi.
yathāsau divy āditya, evam idaṃ śirasi cakṣur.
yathāsāv antarikṣe vidyud, evam idam ātmani hṛdayaṃ.
yathāyam agniḥ pṛthivyām, evam idam upasthe retaḥ \
evam u ha sma sarvalokam ātmānam anuvidhāyāha-.
-idam eva pṛthivyā rūpam, idaṃ divaḥ \
sa ya evam etāṃ saṃhitāṃ veda, saṃdhīyate prajayā paśubhir yaśasā brahmavarcasena svargeṇa lokena.
sarvam āyur eti \\ 2 \\

Next comes the meditation as taught by Sâkalya.

The first half is the earth, the second half heaven, their uniting the rain, the uniter Parganya.

And so it is when he (Parganya) rains thus strongly, without ceasing, day and night,

Then they say also (in ordinary language), 'Heaven and earth have come together.'

So much with regard to the deities; now with regard to the body:--

Every man is indeed like an egg. There are two halves (of him), thus they say: 'This half is the earth, that half heaven.' And there between them is the ether (the space of the mouth), like the ether between heaven and earth. In this ether there (in the mouth) the breath is fixed, as in that other ether the air is fixed. And as there are those three luminaries (in heaven), there are these three luminaries in man.

As there is that sun in heaven, there is this eye in the head. As there is that lightning in the sky, there is this heart in the body; as there is that fire on earth, there is this seed in the member.

Having thus represented the self (body) as the whole world, Sâkalya said: This half is the earth, that half heaven.

He who thus knows this union, becomes united with offspring, cattle, fame, glory of countenance, and the world of Svarga. He lives his full age.