Taittirīya Upaniṣad 2.1

2.1.1

āūṃ saha nāvavatu /
saha nau bhunaktu /
saha vīryaṃ karavāvahai /
tejasvi nāvadhītamastu mā vidviṣāvahai /
āūṃ śāntiḥ śāntiḥ śāntiḥ //
āūṃ brahmavidāpnoti param /
tadeṣā 'bhuktā /
satyaṃ jñānamanantaṃ brahma /
yo veda nihitaṃ guhāyāṃ parame vyoman /
so 'śnute sarvān kāmān saha /
brahmaṇā vipaściteti //
tasmādvā etasmādātmana ākāśaḥ saṃbhūtaḥ /
ākāśādvāyuḥ /
vāyoragniḥ /
agnerāpaḥ /
adabhyaḥ pṛthivī /
pṛthivyā oṣadhayaḥ /
oṣadhībhyonnam /
annātpuruṣaḥ /
sa vā eṣa puruṣo 'nnnarasamayaḥ /
tasyedameva śiraḥ /
ayaṃ dakṣiṇaḥ pakṣaḥ /
ayamuttaraḥ pakṣaḥ /
ayamātmā /
idaṃ pucchaṃ pratiṣṭhā /
tadapyeṣa śloko bhavati // 1//
iti prathamo 'nuvākaḥ //

Om! He who knows Brahma, attains the highest! As to that this [verse] has been declared:—

He who knows Brahma as the real (satya), as knowledge (jñāna), as the infinite (ananta),
Set down in the secret place [of the heart], and in the highest heaven (parame vyoman),
He obtains all desires,
Together with the intelligent (vipaścit) Brahma.

From this Soul (Ātman), verily, space (ākāśa) arose; from space, wind (vāyu); from wind, fire; from fire, water; from water, the earth; from the earth, herbs; from herbs, food; from food, semen; from semen, the person (puruṣa).

This, verily, is the person that consists of the essence of food. This, indeed, is his head; this, the right side; this, the left

side; this, the body (_ātman_); this, the lower part, the foundation.

As to that there is also this verse:—