Putrid
Kaṭuviya Sutta  (AN 3:129)

I have heard that on one occasion the Blessed One was staying near Vārāṇasī in the Deer Park at Isipatana. Then early in the morning the Blessed One, having adjusted his lower robe and carrying his bowl & outer robe, went into Vārāṇasī for alms. As he was walking for alms near the fig-tree at the cattle yoke, he saw a certain monk whose delight was in what is empty, whose delight was in exterior things—his mindfulness muddled, his alertness lacking, his concentration lacking, his mind gone astray, his faculties uncontrolled. On seeing him, the Blessed One said to him: “Monk, monk, don’t let yourself putrefy! On one who lets himself putrefy & stink with the stench of carrion, there’s no way that flies won’t swarm & attack!”

Then the monk—admonished with this, the Blessed One’s admonishment—came to his senses.

So the Blessed One, having gone for alms in Vārāṇasī, after the meal, returning from his alms round, addressed the monks [and told them what had happened].

When this was said, a certain monk said to the Blessed One, “What, lord, is putrefaction? What is the stench of carrion? What are flies?”

“Greed, monk, is putrefaction. Ill will is the stench of carrion. Evil, unskillful thoughts are flies. On one who lets himself putrefy & stink with the stench of carrion, there’s no way that flies won’t swarm & attack.

“On one whose eyes & ears

are unguarded,

whose senses

are unrestrained,

flies                  swarm:

resolves         dependent on passion.

The monk who is putrid,

who stinks of the stench of carrion,

is far from unbinding.

His share is         vexation.

Whether he stays

in village or wilderness,

having gained for himself no

tranquility,

he’s surrounded by flies.

But those who are consummate

in virtue,

who delight

in discernment & calm,

pacified, they sleep in ease.

No flies settle on them.”

See also: SN 9:1; SN 9:11; SN 35:202; AN 3:15; Ud 5:5; Sn 4:7