The Principle of the Power of Saṃgraha (Embracing)

Answer: When reading books or listening to recordings, the mind consciousness must imagine and deliberate, envisioning the corresponding scenes; the components of inference and erroneous cognition are greater, so the effect is poorer and the compelling power weaker. When receiving teaching in person, the component of direct perception is greater, and there is also interaction and resonance between the manas of both parties—a magnetic-field effect—because the manas trusts most what is seen with one's own eyes, and it resonates most readily when one sees with one's own eyes.

When reading a book, the manas does not see with its own eyes; the distance is far, and one must rely on the mind consciousness's deliberation and imagination, so resonance comes slowly and the compelling power is weak. The body language and facial expressions seen on the spot, and the voice heard on the spot, all strengthen one's understanding and feeling, enabling the manas to enhance its direct observation, resonate more readily, and thus the compelling power is strong. Therefore, when the Buddha dwelt in the world, the disciples all stayed close by the Buddha, unwilling to leave Him, for once they left the Buddha, this powerful compelling power was gone.