Shiva Purana
अग्निष्टोमं च यज्ञानां निर्ममे प्रथमान्मुखात् ॥ यजूंषि त्रैष्टुभं छंदःस्तोमं पञ्चदशं तथा ॥ ५९ ॥
From the first mouth of the sacrificial fire he created the fire-god. The Yajur Vedas contain the Traiṣṭubha Veda and the fifteenth Stoma Veda.
english translation
agniSTomaM ca yajJAnAM nirmame prathamAnmukhAt ॥ yajUMSi traiSTubhaM chaMdaHstomaM paJcadazaM tathA ॥ 59 ॥
hk transliteration by Sanscript