Just like a log...

"Monks, do you see that large log being carried along by the current of the river Ganges?"

"Yes, lord."

"Monks, if that log doesn't veer toward the near shore, doesn't veer toward the far shore, doesn't sink in the middle, doesn't get washed up on high ground, doesn't get snared by human beings, doesn't get snared by non-human beings, doesn't get snared in a whirlpool, and doesn't become rotten inside, it will tend to the ocean, tilt to the ocean, incline to the ocean. Why is that? Because the current of the river Ganges tends to the ocean, tilts to the ocean, inclines to the ocean.

"In the same way, monks, if you don't veer toward the near shore, don't veer toward the far shore, don't sink in the middle, don't get washed up on high ground, don't get snared by human beings, don't get snared by non-human beings, don't get snared in a whirlpool, and don't become rotten inside, you will tend to Unbinding, tilt to Unbinding, incline to Unbinding. Why is that? Because right view tends to Unbinding, tilts to Unbinding, inclines to Unbinding."

When this was said, a certain monk addressed the Blessed One: "What, lord, is the near shore? What is the far shore? What is sinking in the middle? What is being washed up on high ground? What is being snared by human beings? What is being snared by non-human beings? What is being snared by a whirlpool? What is becoming rotten inside?"

"'The near shore,' monks, stands for the six internal sense media. 'The far shore' stands for the six external sense media. 'Sinking in the middle' stands for passion & delight. 'Being washed up on high ground' stands for the conceit, 'I am.'

"And what, monks, is being snared by human beings? There is the case where a monk lives entangled with householders, delighting with them and sorrowing with them, happy when they are happy, pained when they are in pain, taking on their affairs as his own duty. This is called being snared by human beings.

"And what, monks, is being snared by non-human beings? There is the case where a certain monk lives the holy life in hopes of a certain company of devas, [thinking,] 'By means of this virtue or practice or austerity or holy life I will become one sort of deva or another.' This is called being snared by non-human beings.

"'Being snared by a whirlpool' stands for the five strings of sensuality.

" And what, monks, is becoming rotten inside? There is the case where a certain monk is unprincipled, evil, unclean and suspect in his undertakings, hidden in his actions, not a contemplative though claiming to be one, not leading the holy life though claiming to do so, inwardly rotten, oozing with desire, filthy by nature. This is called becoming rotten inside."

Daruka-khandha Sutta (The Log)