The Mahabharata/Book 1: Adi Parva…
“ One day a king named Vali conversant with every duty went to the Ganges to perform his ablutions. And as the monarch was thus engaged, the raft to which the Rishi was tied, approached him. And as it came, the king took the old man. The virtuous Vali, ever devoted to truth, then learning who the man was that was thus saved by him, chose him for raising up offspring. And Vali said, 'O illustrious one, it behoveth thee to raise upon my wife a few sons that shall be virtuous and wise.' Thus addressed, the Rishi endued with great energy, expressed his willingness. ”
