Thereafter the materialistic ego of the gigantic form separately manifested itself, and into it entered Rudra, the controller of false ego, with his own partial activities, by which the living entity transacts his objective actions.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
आत्मानं चास्य निर्भिन्नमभिमानोऽविशत्पदम् । कर्मणांशेन येनासौ कर्तव्यं प्रतिपद्यते
ātmānaṃ cāsya nirbhinnamabhimāno'viśatpadam | karmaṇāṃśena yenāsau kartavyaṃ pratipadyate
SB 3.6.25