Kauṣītaki (Śāṅkhāyana) Brāhmaṇa 18.9.30

18.9.30

yady u vā aṣṭā kapālaḥ paurṇamāsam eva tantram bhavati /

cake is offered on five potsherds, for the Paṅkti has five Padas; the sacrifice is fivefold; verily (it serves) to obtain the sacrifice. But, if it is offered on eight potsherds, verily this is the model of the full moon sacrifice; the full moon sacrifice is a support; verily (it serves) for support. In that the invitatory and offering verses are Padapaṅkti verses, this is obviously the symbol of the re-establishment (of the fires). So also are they interwoven. When this has been completed, the sacrificer offers the Agnihotra, for on the completion of the establishment of the fires the Agnihotra is offered; therefore, when this is completed, the sacrificer should offer the Agnihotra, (so they say).