Aruni stops a dike breach and is renamed Uddalaka
When his preceptor orders him to stop a breach in a dike, Aruni finds he cannot do it with earth or stone. He lies down in the breach himself, using his body to hold back the water, and waits until his teacher calls him out.
The sage Ayoda-Dhoumya had three disciples. One day, he gave an order to Aruni of Panchala: go and stop a breach in a dike. Aruni went. He tried, but the water would not be contained. He was sorry for his failure. Then he saw a way.
He entered the breach and lay down in it. The flow of water stopped.
Some time later, Ayoda-Dhoumya asked his other disciples where Aruni was. They reminded him: you sent him to stop the breach. The sage decided to go and see. Arriving at the dike, he called out, "O Aruni of Panchala! Where are you? Come here, my son."
Hearing his preceptor's voice, Aruni rose from the breach. The water began to flow again. He stood before his teacher and explained: "I was in the breach to stop the flow of water that could not be stopped in any other way. It is only when I heard your revered words that I suddenly came to you and allowed the breach again. O Bhagavan! I salute you. Please tell me what your instructions are now."
His preceptor replied, "Since you have opened the flow of waters by standing up from the breach in the dike, you will henceforth be known as Uddalaka." He gave Aruni a new name born from the act — Uddalaka, "the one who opened the dike."
The preceptor also blessed him. "Since you have obeyed my instructions, you will obtain good fortune. All the Vedas will shine in you and also all the dharmashastras (treatises on law and duty)."
Hearing this, Aruni went to the land where he wished to go.