Śatapatha Brāhmaṇa ("of a hundred paths") 5.4.3.2

5.4.3.2

varuṇāddha vā abhiṣiṣicānāt | indriyaṃ vīryamapacakrāma śaśvadya eṣo 'pāṃ rasaḥ sambhṛto bhavati yenainametadabhiṣiñcati so 'syendriyaṃ vīryaṃ nirjaghāna tatpaśuṣvanvavindattasmātpaśavo yaśo yadeṣvanvavindattatpaśuṣvanuvidyendriyaṃ vīryam punarātmannadhatta tatho evaiṣa etannāhaivāsmānnvindriyaṃ vīryamapakrāmati varuṇasavo vā eṣa yadrājasūyamiti varuṇo karoditi tvevaiṣa etatkaroti

When Varuna was consecrated, his energy, his vigour departed from him. Probably that collected essence (life-sap) of the waters wherewith they were sprinkling him, drove out his energy, his vigour. He found it in the cattle, and because he found it in them, therefore cattle are an object of respect. And having found it in the cattle, he again took to himself his energy, his vigour. And in like manner this one;--that energy does not indeed depart from him, but he does it (thinking), 'This Râgasûya is Varuna's consecration, and Varuna did so.'