Vaṇṇupatha Jātaka (No.2)
The Bodhisatta was once the leader of a caravan of five hundred carts. One night, while crossing a desert of sixty leagues, in the last stage of a journey, the pilot fell asleep and the oxen turned round. All the wood and water was finished, but the Bodhisatta made the men dig a well. After digging sixty cubits down they came upon a rock. The men were filled with despair, but the Bodhisatta had the rock broken through by a serving lad who still showed courage and thus obtained water.
The story was related about a young man of Sāvatthi who entered the Order and practiced meditation, but was unable to attain insight. He was filled with despair and his companions took him to the Buddha. He is identified with the serving lad of the story. J.i.106‑110.