Paṭhamachiggaḷayuga sutta: A Yoke With a Hole (1st)

“Mendicants, suppose a person were to throw a yoke with a single hole into the ocean. And there was a one-eyed turtle who popped up once every hundred years.

What do you think, mendicants? Would that one-eyed turtle, popping up once every hundred years, still poke its neck through the hole in that yoke?”

“Only after a very long time, sir, if ever.”

“That one-eyed turtle might poke its neck through the hole in that yoke, but in any case it’d be sooner than a fool fallen to the underworld is reborn as a human being, I say.

Why is that? Because in that place there’s no principled or moral conduct, and no doing what is good and skillful. There they just prey on each other, preying on the weak. Why is that? It’s because they haven’t seen the four noble truths. What four? The noble truths of suffering, its origin, its cessation, and the path.

That’s why you should practice meditation …”