Kauṣītaki (Śāṅkhāyana) Brāhmaṇa 26.3.4

26.3.4

tāv etau trivṛt pañcadaśau stomau saptamam ahar vahataś catur viṃśa stomo bhūtvā / (soma: chandomāh)

xxvi. 7. On the sixth day the gods obtained the Stomas and the months; having obtained these Stomas they compressed these same Stomas in couples, being the Stomas of the Pṛṣṭhya, for whence could they have obtained another Stoma? The Trivṛt and the Pañcadaça Stomas becoming the Caturviṅça Stoma support the seventh day; the Saptadaça and the Triṇava Stomas, becoming the Catuṣcatvāriṅça Stoma, support the eighth day; the Ekaviṅça and the Trayastriṅça Stomas, becoming the Aṣṭācatvāriṅça Stoma, support the ninth day. Of them the first is measured by the Gāyatrī, the second by the Triṣṭubh, the third by the Jagatī; in that they are measured by the metres, therefore are they Chandomas. The six Stotriyā verses which are over the Aṣṭācatvāriṅça Stoma, these they call the seasons; the seasons are six; by these the tenth day is performed.