Bhagavad Gita 7.6एतद्योनीनि भूतानि सर्वाणीत्युपधारय।अहं कृत्स्नस्य जगतः प्रभवः प्रलयस्तथा ॥

These two Natures, the inferior and the superior, are the womb of all beings. As I am the source of these two Prakritis or Natures also, I am the cause of this universe. The whole universe originates from Me and dissolves in Me.In the Brahma Sutras (chapter 1, section 1, aphorism 2) it is said, Janmadyasya yatah meaning that Brahman is that omniscient and omnipotent cause from which proceed the origin, subsistence and dissolution of this world.Just as the mind is the material cause and also the seer (Drashta) for the objects seen in a dream, so also Isvara is the material cause of this world (UpadanaKarana) and also the seer (Drashta). He is also the efficient or the instrumental cause (NimittaKarana). (Cf.XIV.3)