dilipas tat-sutas tadvad
asaktah kalam eyivan
bhagirathas tasya sutas
tepe sa sumahat tapah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Like Amsuman himself, Dilipa, his son, was unable to bring the Ganges to this material world, and he also became a victim of death in due course of time. Then Dilipa’s son, Bhagiratha, performed very severe austerities to bring the Ganges to this material world.