佛說觀佛三昧海經 7.7

7.7

The Buddha told Ānanda: "Now uphold this realm of meditative mindfulness and expound it widely for all sentient beings in future ages. This is called the realm of divine power of the Buddhas; to lose this matter is called slandering the Buddha and severing the seed of bodhi. One who upholds this teaching will not be possessed by demonic spirits and will constantly be sheltered and aided by the Buddhas."