Mbh 1.98.2b

But, O Bharata, those children, one after another, as soon as they were born, were thrown into the river by Ganga who said, ‘This is for thy good.’ And the children sank to rise no more. The king, however, could not be pleased with such conduct. But he spoke not a word about it lest his wife should leave him. But when the eighth child was born, and when his wife as before was about to throw it smilingly into the river, the king with a sorrowful countenance and desirous of saving it from destruction, addressed her and said, ‘Kill it not! Who art thou and whose? Why dost thou kill thy own children? Murderess of thy sons, the load of thy sins is great!’” His wife, thus addressed, replied, ‘O thou desirous of offspring, thou hast already become the first of those that have children. I shall not destroy this child of thine. But according to our agreement, the period of my stay with thee is at an end. I am Ganga, the daughter of Jahnu. I am ever worshipped by the great sages; I have lived with thee so long for accomplishing the purposes of the celestials. The eight illustrious Vasus endued with great energy had, from Vasishtha’s curse, to assume human forms. On earth, besides thee, there was none else to deserve the honour of being their begetter. There is no woman also on earth except one like me, a celestial of human form, to become their mother. I assumed a human form to bring them forth. Thou also, having become the father of the eight Vasus, hast acquired many regions of perennial bliss. It was also agreed between myself and the Vasus that I should free them from their human forms as soon as they would be born. I have thus freed them from the curse of the Rishi Apava. Blest be thou; I leave thee, O king! But rear thou this child of rigid vows. That I should live with thee so long was the promise I gave to the Vasus. And let this child be called Gangadatta.’”