諸經要集 3.8

3.8

As the Guanfo sanmei jing states: The Buddha left his shadow in a stone chamber beside the poisonous dragon pool in the country of Nagarahāra. The Buddha sat in the dragon's stone cave, performed eighteen transformations for the dragon, and leaped his body into the stone. Like a bright mirror, it reflects outwards from within the stone; looking from afar one can see it, but looking up close it does not appear. Hundreds of thousands of devas make offerings to the Buddha's shadow, which also appears preaching the Dharma (it has not perished to this day, and will be transmitted until Maitreya).