Śatapatha Brāhmaṇa ("of a hundred paths") 5.3.4.28

5.3.4.28

tā agreṇa maitrāvaruṇasya dhiṣṇyaṃ sādayati | anādhṛṣṭāḥ sīdata sahaujasa ityanādhṛṣṭāḥ sīdata rakṣobhirityevaitadāha sahaujasa iti savīryā ityevaitadāha mahi kṣatraṃ kṣatriyāya dadhatīriti tatpratyakṣaṃ kṣatraṃ yajamānāyāśiṣamāśāste yadāha mahi kṣatraṃ kṣatriyāya dadhatīriti

He deposits them in front of the Maitrâvaruna's hearth, with, 'Unimpaired rest ye, the strengthful!'--'unimpaired by the Rakshas rest ye!' he thereby says; and by 'strengthful' he means to say 'powerful; 'bestowing great power on the Kshatriya;'--in saying this he prays in an overt way for power to the Sacrificer.