Matsyapurana 12.10

12.10

ikṣvākoraśvamedhena yatphalaṃ syāttadāvayoḥ
dattvā kimpuruṣo vīraḥ sa bhaviṣyatyasaṃśayam //

Vasiṣṭha said that, by devoutly worshipping Śiva, the monarch could be restored to manhood. Hearing that, the brothers of Ila (Sons of Manu) repaired to the abode of Śiva; where they pleased Him by their devotion. The God then said that He could not go against His determination, but that if Ikṣwâku performed the aśvamedha sacrifice, then Ilâ would become a Kimpuruṣa (Mongolian type ?), though it would be impossible for him to assume his previous (Aryan ?) form. After that, the brothers of Ila performed the aśvamedha sacrifice, and the latter became a Kimpuruṣa.—8-11.