The works of Ādi Śaṅkarācārya

Chāndogyopaniṣadbhāṣyam

Avatarika

Avatarika

तौ ह पुनः प्रजापतिरुवाच च्छायात्मनिश्चयापनयाय-

In plain words

Prajāpati spoke to them once again, specifically to dispel their mistaken conviction that the shadow-reflection is the true self.

Close to the Sanskrit

Prajāpati spoke to those two again, for the removal of the certainty of the shadow-self.