Chandogya Upanishad
agnir hiṅkāraḥ vāyuḥ prastāvaḥ āditya udgīthaḥ nakṣatrāṇi pratihāraḥ candramā nidhanam etad rājanaṃ devatāsu protam
The hinkâra is fire, the prastâva air, the udgîtha the sun, the pratihâra the stars, the nidhana the moon. That is the Râgana Sâman, as interwoven in the deities.
sa ya evam etad rājanaṃ devatāsu protaṃ veda etāsām eva devatānāṃ salokatāṃ sarṣṭitāṃ sāyujyaṃ gacchati sarvam āyur eti jyog jīvati mahān prajayā paśubhir bhavati mahān kīrtyā brāhmaṇān na nindet tad vratam
He who thus knows the Râgana, as interwoven in the deities, obtains the same world, the same happiness, the same company as the gods, he reaches the full life, he lives long, becomes great with children and cattle, great by fame. His rule is, 'Do not speak evil of the Brâhmanas.'