Yoga Sutras of Patanjali translated by Yogi Kalinath - Chapter 3, Verse 33
Pada 3, Sutra 33
Praatibhaad vaa sarvam
From the flash of illumination, all knowledge is acquired.
Flash of illumination is the direct mirror reflection of Consciousness itself and as knowledge of any and all kind emerges from Consciousness itself, all knowledge is therefore and thereby acquired.
It takes a quiet mind, where the inner chatter and image faculty is quelled, in order for a flash of illumination to occur. This flash of illumination is Intuition where the Yogi has direct perception of Consciousness itself whereby he/she becomes the knower of all knowledge.
The Nature of the Mind is Light. That Light emerges from Consciousness itself. One who realizes that Light becomes Consciousness, i.e. Self-realized. Knowledge itself is Light, the mind shining its own Light, the process of conscious awareness.