Shatapatha Brahmana 6.7.1.7

6.7.1.7

abhi śuklāni ca kṛṣṇāni ca lomāni niṣyūto bhavati | ṛkṣāmayorhaite rūpe ṛkṣāme vā etaṃ yantumarhata ṛkṣāmābhyāmetaṃ devā abibharurṛkṣāmābhyāmevainametadbibharti śāṇo rukbhapāśastrivṛttasyokto bandhuḥ

It is sown into the white and black hair, for these two are forms of the rik (hymn-verse) and the sâman (hymn-tune), and the rik and sâman are indeed able to sustain him (Agni): by the rik and sâman the gods carried him, and by the rik and sâman he now carries him. The hempen sling of the gold plate is a triple (cord): the significance of this has been explained.