On one occasion the Blessed One was dwelling at Kimbila on the bank of the river Ganges. The Blessed One saw a great log being carried along by the current of the river Ganges, and he addressed the bhikkhus thus: “Do you see, bhikkhus, that great log being carried along by the current of the river Ganges?”

“Yes, venerable sir.”… as above …

When this was said, the Venerable Kimbila asked the Blessed One: “What, venerable sir, is the near shore … what is inward rottenness?”

Replies as above except the following:

“And what, Kimbila, is inward rottenness? Here, Kimbila, a bhikkhu commits a certain defiled offence, an offence of a kind that does not allow for rehabilitation. This is called inward rottenness.”