Saṃyuktāgama 206. [First Discourse at Jīvaka’s Mango Grove]
Thus have I heard. At one time the Buddha was staying at Vesālī in Jīvaka’s Mango Grove.
At that time the Blessed One said to the monks: “You should make a diligent effort at meditation, calm the mind within. Why is that? Monks, in this way diligently practising meditation and calming the mind within, one understands [things] as they really manifest. What does one understand as it really manifests? One understands as it really manifests the eye, and one also understands as they really manifest forms, eye-consciousness, eye-contact, and feeling arisen in dependence on eye-contact, be it painful, pleasant, or neutral.
“The ear … the nose … the tongue … the body … the mind is also like that. All these things are impermanent and conditioned, and in this way one understands them also as they really manifest.”
When the Buddha had spoken this discourse, hearing what the Buddha had said the monks were delighted and received it respectfully.