SB 9.1.22
tasmai kama-varam tusto
bhagavan harir isvarah
dadav ilabhavat tena
sudyumnah purusarsabhah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Supreme Personality of Godhead, the supreme controller, being pleased with Vasistha, gave him the benediction he desired. Thus Ila was transformed into a very fine male named Sudyumna.