Chandogya Upanishad 2.21

trayī vidyā hiṅkāraḥ traya ime lokāḥ sa prastāvaḥ agnir vāyur ādityaḥ sa udgīthaḥ nakṣatrāṇi vayāṃsi marīcayaḥ sa pratihāraḥ sarpā gandharvāḥ pitaras tan nidhanam etat sāma sarvasmin protam

The hinkâra is the threefold knowledge, the prastâva these three worlds, the udgîtha Agni (fire), Vâyu (air), and Âditya (sun), the pratihâra the stars, the birds, and the rays, the nidhana the serpents, Gandharvas, and fathers. That is the Sâman, as interwoven in everything.

sa ya evam etat sāma sarvasmin protaṃ veda sarvaṃ ha bhavati

He who thus knows this Sâman, as interwoven in everything, he becomes everything.

tad eṣa ślokaḥ yāni pañcadhā trīṇi trīṇi tebhyo na jyāyaḥ param anyad asti

And thus it is said in the following verse: 'There are the fivefold three (the three kinds of sacrificial knowledge, the three worlds &c. in their fivefold form, i.e. as identified with the hinkâra, the prastâva, &c), and the other forms of the Sâman. Greater than these there is nothing else besides.'

yas tad veda sa veda sarvam sarvā diśo balim asmai haranti sarvam asmīty upāsita tad vrataṃ tad vratam

He who knows this, knows everything. All regions offer him gifts. His rule is, 'Let him meditate (on the Sâman), knowing that he is everything, yea, that he is everything.'