SB 3.26.20

viśvam ātma-gataṁ vyañjan
 kūṭa-stho jagad-aṅkuraḥ
sva-tejasāpibat tīvram
 ātma-prasvāpanaṁ tamaḥ
Synonyms: 
viśvam — the universe; ātma-gatam — contained within itself; vyañjan — manifesting; kūṭa-sthaḥ — unchangeable; jagat-aṅkuraḥ — the root of all cosmic manifestations; sva-tejasā — by its own effulgence; apibat — swallowed; tīvram — dense; ātma-prasvāpanam — which had covered the mahat-tattva; tamaḥ — darkness.
Translation: 
Thus, after manifesting variegatedness, the effulgent mahat-tattva, which contains all the universes within itself, which is the root of all cosmic manifestations and which is not destroyed at the time of annihilation, swallows the darkness that covered the effulgence at the time of dissolution.
Purport: 

Since the Supreme Personality of Godhead is ever existing, all-blissful and full of knowledge, His different energies are also ever existing in the dormant stage. Thus when the mahat-tattva was created, it manifested the material ego and swallowed up the darkness which covered the cosmic manifestation at the time of dissolution. This idea can be further explained. A person at night remains inactive, covered by the darkness of night, but when he is awakened in the morning, the covering of night, or the forgetfulness of the sleeping state, disappears. Similarly, when the mahat-tattva appears after the night of dissolution, the effulgence is manifested to exhibit the variegatedness of this material world.