This story was narrated by Rishi Lomasha to Yudhishthira during the latter's pilgrimage (Mahabharata, Vana Parva, Tirthayatra Parva)

Mandhata

King Yuvanashva was born in the Ikshvaku clan. That protector of the earth performed many sacrificial rites noted for magnificent gifts. He performed a thousand times the ceremony of sacrificing a horse. He also performed other sacrifices of the highest order, wherein he made abundant gifts. But that saintly king had no son. He made over to his ministers the duties of the state, and became a constant resident of the woods. He devoted himself to the pursuits enjoined in the sacred writ. Once that king had observed a fast. He was suffering from the pangs of hunger and his inner soul seemed parched with thirst. In this state, he entered the hermitage of Bhrigu. On that very night, that great saint had officiated in a religious ceremony, with the object that a son might be born to Saudyumni. At the spot stood a large jar filled with water, consecrated with the recitation of sacred hymns, and which had been previously deposited there. The water was endued with the virtue that the wife of Saudyumni would by drinking the same, bring forth a god-like son. Those mighty saints had deposited the jar on the altar and had gone to sleep, having been fatigued by keeping up the night. As Saudyumni passed them by, his palate was dry, and he was suffering greatly from thirst. And the king was very much in need of water to drink. He entered that hermitage and asked for drink. Becoming fatigued, he cried in feeble voice, proceeding from a parched throat, which resembled the weak inarticulate utterance of a bird. His voice reached nobody's ears. Then the king beheld the jar filled with water. He quickly ran towards it, and having drunk the water, put the jar down. As the water was cool, and as the king had been suffering greatly from thirst, the draught of water relieved the sagacious monarch and appeased his thirst.

Then those saints together with him of ascetic wealth, awoke from sleep; and all of them observed that the water of the jar had gone. Thereupon they met together and began to enquire as to who might have done it. Then Yuvanashva truthfully admitted that it was his act. Then the revered son of Bhrigu spoke unto him, saying, “It was not proper. This water had an occult virtue infused into it, and had been placed there with the object that a son might be born to you. Having performed severe austerities, I infused the virtue of my religious acts in this water, that a son might be born to you. A son would have been born to you of exceeding strength and valour, and strengthened by austerities, and who would have sent by his bravery even Indra to the abode of the god of death. It was in this manner that this water had been prepared by me. By drinking this water, you have done what was not at all right. But it is impossible now for us to turn back the accident which has happened. Surely what you have done must have been the fiat of Fate. Since you being athirst have drunk water prepared with sacred hymns, and filled with the virtue of my religious labours, you must bring forth out of your own body a son of the character described above. To that end we shall perform a sacrifice for you, of wonderful effect so that, valorous as you are, you will bring forth a son equal to Indra. Nor with you experience any trouble on account of the labour pains.”

Then when one hundred years had passed away, a son shining as the sun pierced the left side of the king endowed with a mighty soul, and came forth. The son was possessed of mighty strength. Nor did Yuvanashva die, which itself was strange. Then Indra of mighty strength came to pay him a visit. The deities enquired of the great Indra, “What is to be sucked by this boy?” Then Indra introduced his own forefinger into his mouth. When the wielder of the thunderbolt said, “He will suck me,” the dwellers of heaven together with Indra christened the boy Mandhata, (literally, Me he shall suck). Then the boy having tasted the forefinger extended by Indra, became possessed of mighty strength, and he grew thirteen cubits! The whole of sacred learning together with the holy science of arms, was acquired by that masterful boy, who gained all that knowledge by the simple and unassisted power of his thought. All at once, the boy celebrated under the name of Ajagava and a number of shafts made of horn, together with an impenetrable coat of mail, came to his possession on the very same day! He was placed on the throne by Indra himself and he conquered the three worlds in a righteous way, as Vishnu did by his three strides. The wheel of the car of that mighty king as irresistible in its course throughout the world. The gems, of their own accord, came into the possession of that saintly king.

He performed a number of sacrificial rites of various kinds, in which abundant gratuities were paid to the priests. He erected sacred piles, and performed splendid pious deeds, and attained the position of sitting at Indra's side. That sagacious king of unswerving piety sent forth his fiat, and simply by its virtue conquered the earth, together with the sea! The sacrificial grounds prepared by him were to be found all over the earth on all sides round, not a single spot, but was marked with the same. The mighty monarch is said to have given to the Brahmanas ten thousand padmas of kine. When there was a drought, which continued for twelve consecutive years, the mighty king caused rain to come down for the growth of crops, paying no heed to Indra, who remained staring. The mighty ruler of the Gandhara land, born in the lunar dynasty of kings, who was terrible like a a roaring cloud, was slain by him, who wounded him sorely with his shafts. He protected the four orders of people, and by him of mighty force the worlds were kept from harm, by virtue of his austere and righteous life.