Thus I have heard: One time, the Buddha was staying at Anāthapiṇḍada’s Park in Jeta’s Grove of Śrāvastī.
It was then that the Bhagavān addressed the monks, “I don’t see a single thing as quick as the mind. It cannot be grasped without using the method of the Dharma, and then the mind spins around quickly. Therefore, monks, ordinary people are unable to observe their mind thinking.
“Therefore, monks, one should control their thinking to lead their mind to the good path. Thus, monks, you should train yourselves.”
When the monks heard what the Buddha taught, they rejoiced and approved.