Mandukya Karika, verse 4.64


स्वप्नदृक्चित्तदृश्यास्ते न विद्यन्ते ततः पृथक् ।
तथा तद्दृश्यमेवेदं स्वप्नदृक्चित्तमिष्यते ॥ ६४ ॥

svapnadṛkcittadṛśyāste na vidyante tataḥ pṛthak |
tathā taddṛśyamevedaṃ svapnadṛkcittamiṣyate || 64 ||

64. These (beings) which are objects of the mind of the dreamer have no existence apart from his mind. Similarly, this mind of the dreamer is admitted to be the object of perception of the dreamer only. (Therefore the mind of the dreamer is not separate from the dreamer himself)

Shankara Bhashya (commentary)

Those1 beings perceived by the mind of the dreamer have no existence outside the mind of the person who dreams about them. It2 is the mind alone which imagines itself to have assumed the forms of many diversified beings. Similarly,3 that mind of the dreamer is, again, perceived by the dreamer alone. Therefore there is no separate thing called mind which is apart from the dreamer himself.