Reading Notes: Ancestors of Rama
Dilipa and Sudakshina were sad for they had no children. So they decide to visit a sage. Apparently, they passed a divine cow named Surabhi and she cursed them to never have kids for not paying their respects to her. The sage tells them they must serve Nandini the divine cow's daughter. So every day Sudakshina worshipped Nandini and then brought her into the forest who was then watched over by Dilipa; at the end of each day Nandini was brought back out of the forest to Sudakshina. One day to test Dilipa a lion attacks Nandini, the lion says he's guarding a tree for the gods and Nandini trespassed so she must die. Dilipa begs the lion to take his life instead of Nandini's. It ended up being an illusion created by Nandini. Nandini blessed the for Dilipa's actions with a son which they named Raghu. Raghu grows up to be a mighty prince and warrior. Dilipa is trying to perform 100 sacrifices and Indra is determined to keep the title solely for himself, so he goes invisible and steals the horse. Nandini having favor for Raghu blesses him with the vision to see and shoots Indra out of the sky. he bests Indra so Indra gives him anything he wants except the horse and Raghu asks for his father to be given the title of 100 sacrifices. Dilipa makes Raghu king for this and retires into the forest with Sudakshina.
The Sage discussing Raghu's atonement with respect to Nandini
Chandrakant, Kamala, et al. Ancestors of Rama: a Noble Inheritance. Amar Chitra Katha, 2014.