Saṃyuktāgama 212. [Discourse on Cultivating Diligence]
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: “I do not say to all monks that they [should] cultivate diligence, and I also do not say to all monks that they [should] not cultivate diligence.
“In relation to what type of monk do I not say that he [should] cultivate diligence? If a monk has become an arahant and has eradicated all the influxes, he is free from the heavy burdens, has gained his own benefit, eradicated all the fetters of existence, and his mind has been rightly liberated.
“To a type of monks like this I do not say that they [should] cultivate diligence. Why is that? Because such monks have already undertaken [the cultivation of] diligence, they are no more capable of undertaking a negligent matter. Because I now see that those venerable ones have attained the fruit of diligence, I do not say to them that they [should] cultivate diligence.
“In relation to what type of monks do I say that they [should] cultivate diligence? If monks are at the stage of a trainee (sekha), they have not yet attained the supreme appeasement of the mind and are [still] proceeding towards becoming established in Nirvāṇa.
“To a type of monks like this I say that they [should] cultivate diligence. Why is that? As such a monk trains in the faculties and delights the mind accordingly, is endowed with the necessities of life, and associates with good friends, he will soon attain the destruction of the influxes, the influx-free liberation of the mind and liberation by wisdom, knowing here and now for himself and realizing that: ‘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.’
“Why is that? In relation to forms cognized by the eye which he could crave for with delight and become defiled by attachment, on having seen them that monk does not delight in them, does not praise them, is not defiled by them, and is not established in the bondage of attachment. As he does not delight in them, not praise them, is not defiled by them, and is not established in [the bondage of] attachment, he diligently progresses in the appeasing of body and mind.
“With the mind fully established in peace without forgetfulness, always concentrated and single-minded, with boundless joy in the Dharma, but still attaining the foremost concentrative attainment, he will certainly not regress by following a form with the eye. In relation to [sounds cognized by] the ear … [odours cognized by] the nose … [flavours cognized by] the tongue … [tangibles cognized by] the body … mind-objects cognized by the mind it is also like this.”
When the Buddha had spoken this discourse, hearing what the Buddha had said the monks were delighted and received it respectfully.