Yoga Sūtra Chapter Four verse 21

चित्तान्तर दृश्ये बुद्धिबुद्धेः अतिप्रसङ्गः स्मृतिसंकरश्च ॥२१॥

citta-antara-dṛśye buddhi-buddheḥ atiprasaṅgaḥ smṛti-saṃkaraḥ ca ||21||

One psyche seen by another
is an infinite coming together of comprehension with comprehension
and remembrance completely mixed.

citta - psyche (the totality of the human mind, conscious and unconscious); mind; heartantara - other; different; another; being in the interior, interiordṛśya - the seen; to be seen, visiblebuddhi - the intellectual faculty; comprehension; intelligence, discernment, judgementatiprasaṅga - infinite coming togethersmṛti - remembrance; memory; mindfulness; the whole body of sacred tradition or what is remembered by human teachers and constantly revisedsaṃkara - completely mixed, mixing together, commingling, intermixtureca - and

Commentaries and Reflections

Commentary by S Ramaswami:

“If whatever is observed by one mind is observed by another mind, this process would go on endlessly.
This implies that memory would not be possible if Buddhi was the conscious principle.
Thus the argument is used to justify a permanent entity which is beyond this process.
Also if there were endless Citta the memory would be confused.
The Buddhist view is that the momentary consciousness of a momentary existence of Cittavṛttis. They say that there is no Citta only Cittavṛtti.”