Saṃyuktāgama 188. [Discourse on Freedom from Delight and Lust]
Thus have I heard. At one time the Buddha was staying at Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s Park.
At that time the Blessed One said to the monks: “You should rightly examine the eye as impermanent. One who examines it like this is called ‘with right view’. Because of rightly contemplating it, disenchantment arises. Because of the arising of disenchantment, one is free from delight and free from lust. Because of being free from delight and lust, I say the mind is rightly liberated.
“In the same way [one should rightly examine] the ear … the nose … the tongue … the body … the mind … [up to] … one is free from delight and free from lust. Monks, because of being free from delight and lust, I say the mind is rightly liberated.
“One whose mind is rightly liberated is able to declare of himself: ‘Birth for me has been eradicated, the holy life has been established, what had to be done has been done, I myself know that there will be no receiving of any further existence.’”
When the Buddha had spoken this discourse, hearing what the Buddha had said the monks were delighted and received it respectfully.
As for being impermanent, in the same way also [discourses] are to be recited in this way for being dukkha, empty, and not-self.