Samyutta Nikaya XIII.2
Pokkharani Sutta
The Pond
Staying at Savatthi. "Suppose, monks, that there were a pond fifty
leagues wide, fifty leagues long, & fifty leagues deep, filled to overflowing
with water so that a crow could drink from it, and a man would draw some
water out of it with the tip of a blade of grass. What do you think? Which
would be greater: the water drawn out with the tip of the blade of grass
or the water in the pond?"
"The water in the pond would be far greater, lord. The water drawn out
with the tip of the blade of grass would be next to nothing. It wouldn't
be a hundredth, a thousandth, a one hundred-thousandth -- the water drawn
out with the tip of the blade of grass -- when compared with the water
in the pond."
"In the same way, monks, for a noble disciple who is consummate in view,
an individual who has broken through [to stream-entry], the suffering &
stress that is totally ended & extinguished is far greater. That which
remains in the state of having at most seven remaining lifetimes is next
to nothing: it's not a hundredth, a thousandth, a one hundred-thousandth,
when compared with the previous mass of suffering. That's how great the
benefit is of breaking through to the Dhamma, monks. That's how great the
benefit is of obtaining the Dhamma eye."