The Bodhisatta was once a king of monkeys and he led a troop of eighty thousand. To protect them from danger he had instructed them to ask him before eating any fruit they had not seen before or drinking from any water source they had not used before. One time as the troop roamed the forest some monkeys came upon a new lake, so they sat and waited for the Bodhisatta to arrive. He examined the shore and saw that all footprints led into the water and none led out, so he knew that an ogre haunted it.
When the frustrated ogre saw that the monkeys were not going to enter the water, he emerged and begged the monkeys to go in so he could eat them. The Bodhisatta, however, came up with a plan to drink the water without entering it. He took a reed from the shore and blew into the end of it, miraculously turning it hollow. He then commanded that all reeds growing around this lake turn hollow, and they have stayed so ever since. Then all eighty thousand monkeys took a seat around the lake and drank their fill through one of these special reeds.
In the Lifetime of the Buddha
While on a pilgrimage the Buddha’s disciples sent the novices out to collect reeds to use as needle cases. But all the reeds they found were completely hollow with no nodes inside. They asked the Buddha how this could be and he told them this story to explain.
The ogre was an earlier birth of Devadatta, a disciple of the Buddha who became his nemesis. The eighty thousand monkeys were earlier births of the Buddha’s disciples.