Thereafter, when His consciousness separately manifested itself, the total energy, mahat-tattva, entered with His conscious part. Thus the living entity is able to conceive specific knowledge.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
सत्त्वं चास्य विनिर्भिन्नं महान् धिष्ण्यमुपाविशत् । चित्तेनांशेन येनासौ विज्ञानं प्रतिपद्यते
sattvaṃ cāsya vinirbhinnaṃ mahān dhiṣṇyamupāviśat | cittenāṃśena yenāsau vijñānaṃ pratipadyate
SB 3.6.26