Taittirīyopaniṣat 01.18

pṛthivyantarikṣaṃ dyaurdiśo'vāntaradiśāḥ। agnirvāyurādityaścandramā nakṣatrāṇi। āpa oṣadhayo vanaspataya ākāśa ātmā। ityadhibhūtam। athādhyātmam। prāṇovyāno'pāna udānaḥ samānaḥ। cakṣuḥ śrotraṃ mano vāk tvak। carma māṃsaṃ snāvā'sthimajjā। etadadhi vidhāya ṛṣiravocat। pāṅktaṃ vā idagm sarvam। pāṅktenaiva pāṅktaṃ spṛṇotīti ॥18॥

Earth, atmosphere, sky, directions, and intermediate directions; fire, wind, sun, moon, and stars; waters, herbs, trees, space, and ego-principle — these are the elements. Now, pertaining to spiritual knowledge (adhyātmam): prāṇa, vyāna, apāna, udāna, and samāna; eye, ear, mind, speech, and skin; hide, flesh, sinews, bone, and marrow. Having arranged these, the sage declared: "All this is indeed fivefold. By the fivefold alone, the fivefold is completed."

Taittirīya Bhāshya 01.18

The word 'ātmā' in this context refers to the principle of ego. A reference is provided to a testimonial from Tattvasaṁhitā where Lord Hari, beginning with Nārāyaṇa empowers the six groups of five elements.

"pṛthivyādyaṃ pāṅktaṣaṭkaṃ pāṅktenaiva svayaṃ hariḥ। nārāyaṇādirūpeṇa balayatyañjasā prabhuḥ। ityuvāca svayaṃ viṣṇuḥ vedadraṣṭā guṇādhikaḥ॥"

"Lord Hari himself, in the form beginning with Lord Nārāyaṇa, empowers the six groups of five elements beginning with earth by the fivefold principle; thus spoke Lord Viṣṇu himself, the seer of the Veda and one endowed with supreme qualities."

iti tattvasaṁhitāyām॥

- stated thus in the Tattvasaṁhitā.

ātmā ahaṅkāratattvam॥

The word 'ātmā' in this context refers to the principle of ego.