The Shruti declares,-Day was not. Night was not. Aught was not. Naught was not. In the beginning there was only Ignorance. She was of the form of the universe, and she is the night of Narayana of universal form. This is the meaning of the word of Tamas.
नासीदहो न रात्रिरासीन्न सदासीन्नासदासीत् तम एव पुरस्तादभवद् विश्वरूपम्। सा विश्वरूपस्य रजनी हि एवमस्यार्थोऽनुभाष्या॥