佛說處處經 1.40

1.40

The Buddha said: "When King Pukkusāti walked to the twelve gates, he returned without knowing the six elements in his body. Focusing the mind, one can attain the Way, but he did not know that the body produces the mind and the mind produces the body, unable to distinguish them. The Buddha knew he could be liberated, so he went to stay overnight with him, but the king did not know it was the Buddha. The Buddha asked: 'What teaching do you practice, O King, and what Way do you delight in?' and his body hair stood on end. The Buddha explained to him the emptiness of matters within the body, whereupon he attained the Way. If one does not cut off everything completely, one does not attain arhatship." The Buddha said: "All practitioners should know that the mind can attain the Way."