Shiva Purana
तस्य ब्रह्मषडंगानि प्रथमावरणं स्मृतम् ॥ द्वितीयावरणे चैव विद्येश्वरमयं तथा ॥ ५१ ॥
The six Vedic mantras are the first covering of the universe. The second covering is also made of the Lord of knowledge.
english translation
tasya brahmaSaDaMgAni prathamAvaraNaM smRtam ॥ dvitIyAvaraNe caiva vidyezvaramayaM tathA ॥ 51 ॥
hk transliteration by Sanscript