Kaivalyapaad, Yogsutra 4.19
न तत् स्वाभासं दृश्यत्वात् ॥ ४.१९ ॥
na tat svaabhaasam drshyatvaat || 4.19 ||
na - not
tat - that (chitta)
svaabhaasam - self-illuminating
drshyatvaat - it is the scene, hence
Just like chitta illuminates the object, similarly it can illuminate itself. Then what is the need to accept a seer, distinct from the Chitta? Patanjali explains,
Since the chitta is the drishya or that which is being seen, hence it is not self-illuminating. The consciousness of the chitta is also a reflection of the seer, which is the Purush.