Taittiriya Upanishad 2.5

2.5.1

vijñānaṃ yajñaṃ tanute /
karmāṇi tanute 'pi ca /
vijñānaṃ devāḥ sarve /
brahma jyeṣṭhamupāsate /
vijñānaṃ brahma cedveda /
tasmaccenna pramādyati /
śarīre pāpmano hitvā /
sarvānkāmānsamaśnuta iti /
tasyaiṣa eva śārīra ātmā /
yaḥ pūrvasya /
tasmādvā etasmādvijñānamayāt /
anyo 'ntara ātmā ' 'nandamayaḥ /
tenaiṣa pūrṇaḥ /
sa vā eṣa puruṣavidha eva /
tasya puruṣavidhatām /
anvayaṃ puruṣavidhaḥ /
tasya priyameva śiraḥ /
modo dakṣiṇaḥ pakṣaḥ /
pramoda uttaraḥ pakṣaḥ /
ānanda ātmā /
brahma pucchaṃ pratiṣṭhā /
tadapyeṣa śloko bhavati // 1//
iti pañcamo 'nuvākaḥ //

Understanding directs the sacrifice;
And deeds also it directs.
'Tis understanding that all the gods
Do worship as Brahma, as chief.
If one knows Brahma as understanding,
And if he is not heedless thereto,
He leaves his sins (_pāpman_) in the body,
And attains all desires.

This, indeed, is its bodily self, as of the former.

Verily, other than and within that one that consists of understanding is a self that consists of bliss (_ānanda-maya_). By that this is filled. That one, verily, has the form of a person. According to that one's personal form is this one with the form of a person. Pleasure (_priya_) is its head; delight (_moda_), the right side; great delight (_pra-moda_), the left side; bliss (_ānanda_), the body (_ātman_); Brahma, the lower part, the foundation.

As to that there is also this verse:—