Taittirīyopaniṣat 02.06 and 07

tasmād vā etasmād annarasamayāt। anyo'ntara ātmā prāṇamayaḥ। tena eṣaḥ pūrṇaḥ। sa vā eṣaḥ puruṣavidh eva। tasya puruṣavidhatām। anvayaṃ puruṣavidhḥ। tasya prāṇa eva śiraḥ। vyānaḥ dakṣiṇaḥ pakṣaḥ। apānaḥ uttaraḥ pakṣaḥ। ākāśa ātmā। pṛthivī pucchaṃ pratiṣṭhā ॥6॥

Therefore, from this, which is made of the essence of food, there is another inner self, the prāṇamaya. By this, it is complete. This is indeed in the form of a person. Its person-form-ness is continuous. For it, prāṇa is the head, vyāna is the right side, apāna is the left side, space is the Ātmān, and earth is the tail and support.

tad apyeṣa śloko bhavati। prāṇaṃ devā anu prāṇanti। manuṣyāḥ paśavaś ca ye। prāṇo hi bhūtānām āyaḥ। tasmāt sarvāyuṣam ucyate। sarvam eva ta āyur yaṃti। ye prāṇaṃ brahmopāsate। prāṇo hi bhūtānām āyuḥ। tasmāt sarvāyuṣam ucyata iti। tasaiṣa eva śārīra ātmā। yaḥ pūrvasya ॥7॥

This is also stated in the verse: "The gods follow the life-breath; so do humans and animals. The life-breath is truly the source of all beings, and thus it is called the giver of all life. All indeed attain life who worship the life-breath as Brahman. The life-breath is the life of all beings, and therefore it is called the giver of all life. This indeed is the bodily Ātmān, the same as the previous one."

Taittirīya Bhāshya 02.07

A testimonial from Pancharatra is provided where the Pradyumna form of the lord, taking the shape of prāṇamaya is described. Prāṇa is the head, vyāna is the right side, apāna is the left, the middle is the space, i.e. samāna, and the tail is the earth, is udāna.

"t"syā'taraṃ paraṃ rūmamabhinamapi bhinnavat। pradyumnākhyaṃ prāṇamayaṃ praṇetṛtvāt prakīrtitam॥

"His other, supreme form, though undivided, appears as if divided. It is called Pradyumna, consisting of vital energy (prāṇamayam), and is proclaimed so because it is the guiding principle.

śiras tasya prāṇagataṃ prāṇa ityeva nāmataḥ। vyānākhyō dakṣiṇaḥ pakṣo vyānagaś cottaras tathā॥

The head, where the vital force resides, is known as 'prāṇa'. The right side is called 'vyāna', and similarly, the left side is associated with 'apāna'.

śiras tasya prāṇagataṃ prāṇa ityeva nāmataḥ। vyānākhyo dakṣiṇaḥ pakṣo vyānagaś cottaras tathā। apānākhyo'pānagata ākāśasthaṃ ca madhyamam। ākāśākhyaṃ tathā pucchaṃ pṛthivyāṃ pṛthivināmakam॥

His head, pervaded by prāṇa, is called 'prāṇa'. The right side is known as vyāna, and the left as apāna. The one called vyāna, entered by apāna, is the middle situated in space and is called ākāśa. Likewise, the tail, located in the earth, is named pṛthivī.

viśeṣāc ceṣṭayet yasmād vyāna-ākhyaḥ dakṣiṇaṇaḥ karaḥ। yasmād apanayed doṣān apānaḥ savya ucyate॥

The right hand, known as vyāna, is to be moved with special distinction; the left, called apāna, is that by which faults are removed.

ākāśas tv avakāśatvāt madhyadeho mahātmanaḥ। pr̥thvī puccham asyoktaṃ sarvavyāpi pradhāraṇāt॥

Ether is considered the middle body of the great soul due to its spacious nature; earth is described as his tail, as it supports and pervades everything.

sa yeṣa jagatām āyaḥ..."

He is the source of all the worlds..."