Mbh 12.50.7c

Afterwards, when some thousands of years had passed away, the puissant Rama, who was wrathful by nature, had imputations cast upon him (of cowardice). The grandson of Viswamitra and son of Raivya, possessed of great ascetic merit, named Paravasu, O monarch, began to cast imputations on Rama in public, saying, 'O Rama, were not those righteous men, viz., Pratardana and others, who were assembled at a sacrifice at the time of Yayati's fall, Kshatriyas by birth? Thou art not of true vows, O Rama! Thine is an empty boast among people. Through fear of Kshatriya heroes thou hast betaken thyself to the mountains.' The descendant of Bhrigu, hearing these words of Paravasu, once more took up arms and once more strewed the earth with hundreds of Kshatriya bodies. Those Kshatriyas, however, O king, counting by hundreds, that were spared by Rama, multiplied (in time) and became mighty monarchs on earth. Rama once more slaughtered them quickly, not sparing the very children, O king! Indeed, the earth became once more strewn with the bodies of Kshatriya children of premature birth. As soon as Kshatriya children were born, Rama slaughtered them. Some Kshatriya ladies, however, succeeded in protecting their children (from Rama's wrath). Having made the earth destitute of Kshatriyas for thrice seven times, the puissant Bhargava, at the completion of a horse-sacrifice, gave away the earth as sacrificial present unto Kasyapa. For preserving the remnant of the Kshatriyas, Kasyapa, O king, pointing with his hand that still held the sacrificial ladle, said these words, 'O great sage, repair to the shores of the southern ocean. It behoveth thee not, O Rama, to reside within (what is) my dominion.' At these words, Ocean suddenly created for Jamadagni's son, on his other shore, a region called Surparaka. Kasyapa also, O monarch, having accepted the earth in gift, and made a present of it unto the Brahmanas, entered the great forest.