Thereafter the mahat-tattva differentiated itself into many different forms as the reservoir of the would-be entities. The mahat-tattva is chiefly in the mode of ignorance, and it generates the false ego. It is a plenary expansion of the Personality of Godhead, with full consciousness of creative principles and time for fructification.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
सोऽप्यंशगुणकालात्मा भगवद्दृष्टिगोचरः । आत्मानं व्यकरोदात्मा विश्वस्यास्य सिसृक्षया
so'pyaṃśaguṇakālātmā bhagavaddṛṣṭigocaraḥ | ātmānaṃ vyakarodātmā viśvasyāsya sisṛkṣayā
SB 3.5.28