Reading guide
The teaching in one sentence
Desire is the bitterness, ill will is the putrefaction, and bad thoughts are the flies that a festering mind draws to itself without fail.
The same ground, used differently
Isipatana’s deer park is the most consequential setting in the entire canon — it is where the Buddha delivered his first sermon to the group of five and Koṇḍañña became the first to awaken, told in full in SN 56.11. AN 3.128 uses the identical opening formula, “near Varanasi, in the deer park at Isipatana,” for a scene with none of that weight: an ordinary morning almsround and one disgruntled monk. The same ground carries both, and a teacher can use the contrast directly — not every event at a famous place is itself a famous event.
A monk described precisely
The description is a checklist rather than an insult: rittassādaṁ, empty of inner satisfaction; bāhirassādaṁ, looking for gratification in external things; unmindful, without situational awareness, without immersion, straying mind, undisciplined faculties. Six specific conditions, not a mood. The Buddha does not ask what is wrong before speaking — the diagnosis is made by observation alone, walking past.
Why flies, precisely
The image is unpleasant on purpose. Kaṭuviya is festering, gone bad; āmagandha is the specific smell of raw meat or a corpse; the flies that “without a doubt” come are not a risk but a certainty, stated with the same confidence a warning about physical decay would carry. A reader who flinches at the bluntness is reacting exactly as the discourse intends — the point is to make spiritual neglect as viscerally undeniable as a wound left untreated.
What the three things turn out to be
Asked directly what the bitterness, the putrefaction, and the flies are, the Buddha answers in three matched terms: abhijjhā, desire or covetousness, is the bitterness; byāpāda, ill will, is the putrefaction; and bad, unskillful thoughts generally are the flies. Two of the three — covetousness and ill will — are two-thirds of the canon’s standard trio of mental unwholesome conduct, with the third slot here left open to any bad thought at all rather than narrowed to wrong view specifically.
Guarded senses, and what comes to rest at ease
The verses trace the mechanism: unguarded eyes and ears, unrestrained faculties, and the flies — lustful thoughts — will plague you. The final verse turns the image over to its opposite: those who have ethics, who love wisdom and peace, sleep at ease, having gotten rid of the flies. Nothing exotic is prescribed. Sense restraint alone is what keeps the wound from forming in the first place.
Key terms
The text
A disgruntled monk
§1At one time the Buddha was staying near Varanasi, in the deer park at Isipatana. Then the Buddha robed up in the morning and, taking his bowl and robe, entered Varanasi for alms. While the Buddha was walking for alms near the cow-hitching place at the wavy leaf fig, he saw a disgruntled monk who was looking for pleasure in external things, unmindful, without situational awareness or immersion, with straying mind and undisciplined faculties. The Buddha said to him, “Monk, don’t be bitter. If you’re bitter, festering with putrefaction, flies will, without a doubt, plague and infest you.” Hearing this advice of the Buddha, that monk was struck with a sense of urgency.
Reported to the assembly
§2Then, after the meal, on his return from almsround, the Buddha told the mendicants what had happened. … When he said this, one of the mendicants asked the Buddha: “Sir, what is this ‘bitterness’? What is ‘putrefaction’? And what are the ‘flies’?”
The verses
§3“Desire is bitterness; ill will is the putrefaction; and bad, unskillful thoughts are the flies. If you’re bitter, festering with putrefaction, flies will, without a doubt, plague and infest you. When your eyes and ears are unguarded, and you’re not restrained in your sense faculties, flies—those lustful thoughts—will plague you. A mendicant who’s bitter, festering with putrefaction, is far from being extinguished, distress is their lot. Whether in village or wilderness, if they don’t find serenity in themselves, the fool, the simpleton departs, honored only by flies. But those who have ethics, lovers of wisdom and peace, they, being peaceful, sleep at ease, since they’ve got rid of the flies.”
Self-check quiz
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