Shatapatha Brahmana 9.2.1.18

9.2.1.18

pratyetya pravargyopasadbhyām pracarati | pravargyopasadbhyām pracaryāthāsmai vrataṃ vārdhavrataṃ vā prayacatyatha pravargyopasadbhyāmatha pravargyamutsādayatyāptvā taṃ kāmaṃ yasmai kāmāyainam pravṛṇakti

Having returned (to the hall-fire) he proceeds with the (forenoon performance of the) Pravargya and Upasad; and having performed the Pravargya and Upasad, he hands to him (the Sacrificer) the fast-food or semi-fast-food. He then (proceeds) with the (afternoon performance of the) Pravargya and Upasad, and having obtained the object for which he puts the (Pravargya-) cauldron on the fire, he sets out (the apparatus of) the Pravargya.