長阿含經 18.p28

18.p28

“Ascetics and priests use various methods to enter a fixed samādhi of mind. Following that samādhi of mind, they visualize the removal of the external impurities of skin, muscle, and white bones. They only visualize where their mind and consciousness dwell. Where does it exist in the present life? Where will it exist in a later life? If it’s not ended in the present life and not ended in the later life, then it’s not freed in the present life and not freed in the later life. This is the third attainment of vision.