Shatapatha Brahmana 9.4.4.16

9.4.4.16

atho yathā prāyaṇīye 'tirātre | sāmidhenīranūcya brūyādudayanīya evāto 'nuvaktāsmīti tādṛktattasmādaharahareva yuñjyadaharaharvimuñcet

And, indeed, it would be just as if, at the Prâyanîya Atirâtra, after reciting the kindling-verses, he were to say, 'Hereafter, at the Udayanîya, I shall recite (them again)!' Let him therefore yoke (the altar) day by day, and unyoke it day by day.