Shatapatha Brahmana 2.2.4.4

2.2.4.4

athainamagnirvyāttenopaparyāvavarta | tasya bhītasya svo mahimāpacakrāma vāgvā asya svo mahimā vāgasyāpacakrāma sa ātmannevāhutimīṣe sa udamṛṣṭa tadyadudamṛṣṭa tasmādidaṃ cālomakamidaṃ ca tatra viveda ghṛtāhuti vaiva payāahutiṃ vobhayaṃ ha tveva tatpaya eva

Thereupon Agni turned towards him with open mouth; and he (Pragâpati) being terrified, his own greatness departed from him. Now his own greatness is his speech: that speech of his departed from him. He desired an offering in his own self, and rubbed (his hands); and because he rubbed (his hands), therefore both this and this (palm) are hairless. He then obtained either a butter-offering or a milk-offering;--but, indeed, they are both milk.