Śatapatha Brāhmaṇa ("of a hundred paths") 3.2.2.3

3.2.2.3

tadvā ṛṣīṇāmanuśrutamāsa | te yajñaṃ samabharanyathāyaṃ yajñaḥ sambhṛta evaṃ vā eṣa yajñaṃ sambharati yo dīkṣate vāgvai yajñaḥ

Now this was heard by the Rishis. They collected the sacrifice. As that sacrifice was collected (prepared), so does he who is consecrated collect the sacrifice (by keeping his speech within him),--for the sacrifice is speech.