Upanishads 2.1-2.2

2.1-2.2

jihvā rasaṃ vijānāti hṛdayaṃ vedayat priyam
cakṣurdiṣṭaḥ sākṣibhāgo manasā sādhu paśyati
manasā vācaṃ nayati cakṣuṣā mīyate jagat
bhūtasya karṇau śrotārāvannaṃ prāṇena saṃmitam
annaṃ prāṇo vṛṣādarviḥ parjanyo dattavānmahat
agniśca havyavāhanastadidaṃ gāva iddhaviḥ
vittaṃ bandhuḥ prajātantuḥ karmarūpaṃ bṛhatsakhā
prajñā pratiṣṭhā tantūnāmiṣṭāpūrteḥ parāyaṇam
satyaṃ vadantyanṛtamudrahanti kṣīraṃ pibanti madhu te pibanti
somaṃ pibantyamṛtena sārdhaṃ mṛtyoḥ parastādamṛtā bhavanti
ye brāhmaṇā brahmacaryaṃ carantyatho khalvāhuvedasaṃmito'yamitihāsaḥ
dharmaṃ carati nādharmaṃ satyaṃ vadati nānṛtam
dīrghaṃ paśyati mā hrasvaṃ paraṃ paśyati mā'param
ṛco ha yo veda sa veda devān yajūṃṣi yo veda sa veda yajñam
sāmāni yo veda sa veda sarvaṃ yo mānasaṃ veda sa veda brahma
yaḥ krauḍhryena kruddhastiṣṭhati so'tivācaṃ ca dīkṣayati | yo'tivācaṃ
nayati sa vai sarvaṃ dvijaḥ khalu mānasaṃ vedeti naḥ śrutam
tapo'vadhiḥ paramā brāhmaṇasya śraddhā mātā pitaraṃsatyamāhuḥ
yoga ātmā caraṇamasya bandhurdamaḥ pratiṣṭhā viduṣo na bhūmim
duḥkhaṃ janma jarā duḥkhaṃ duḥkhaṃ mṛtyuḥ punaḥ punaḥ
saṃsāramaṇḍalaṃ duḥkhaṃ pacyante yatra jantavaḥ
yo brāhmaṇaḥ pāpakṛt mantrakṛcca sa jīvati
brahmaṇyo brahmakṛcchaśvat brahmaloke mahīyate
tṛṇāni hīcchanti kuśatvameva vṛkṣā yūpatvaṃ paśavaśca gotvam
sarvāḥ prajā brāhmaṇatvaṃ narendra na brāhmaṇatvāt paramasti kiṃcit
śatāhāvaśataśaraḥ śataśaknaṛjīṣiṇām
śataṃ brahma tapasvināṃ kroḍaraṇyasya tiṣṭhati
ṛtenāpihitā guhā śrutenāpihitā guhā
smṛtenāpihitā guhā śamenāpihitā guhā