Mbh 1.199.2

“Vaisampayana said, ‘Vyasa continued, ‘In days of yore, the celestials had once commenced a grand sacrifice in the forest of Naimisha. At that sacrifice, O king, Yama, the son of Vivaswat, became the slayer of the devoted animals. Yama, thus employed in that sacrifice, did not (during that period), O king, kill a single human being. Death being suspended in the world, the number of human beings increased very greatly. Then Soma and Sakra and Varuna and Kuvera, the Sadhyas, the Rudras, the Vasus, the twin Aswins,--these and other celestials went unto Prajapati, the Creator of the universe. Struck with fear for the increase of the human population of the world they addressed the Master of creation and said, ‘Alarmed, O lord, at the increase of human beings on earth, we come to thee for relief. Indeed, we crave thy protection.’ Hearing those words the Grandsire said, ‘Ye have little cause to be frightened at this increase of human beings. Ye all are immortal. It behoveth you not to take fright at human beings.’ The celestials replied, ‘The mortals have all become immortal. There is no distinction now between us and them. Vexed at the disappearance of all distinction, we have come to thee in order that thou mayest distinguish us from them.’ The Creator then said, ‘The son of Vivaswat is even now engaged in the grand sacrifice. It is for this that men are not dying. But when Yama’s work in connection with the sacrifice terminates, men will again begin to die as before. Strengthened by your respective energies, Yama will, when that time comes, sweep away by thousands the inhabitants on earth who will scarcely have then any energy left in them.’