Dilip was the King of Ayodhya. He did not had any child. One day he went to sage Vasishta’s hermitage with wife and requested sage that they want a son. Through meditation Sage Vasishta got to know the reasons behind why they were not having a child. Sage Vasishts said “King! When you were coming back from heaven to earth after meeting Devraj Indra, then you did not bow in front of Kamdehnu who was standing on the way. Kamdhenu cursed you that without serving her child you can't become a father.”
King Dilipa said “Sage! All cow are Kamdhenu children, serving cow is a great pious work. I will serve the cow.” Sage Vasishta told him” in my hermitage there is a cow name Nandini. She is Kamdehnu's daughter. You serve her.”
King Dilipa in the morning went to forest to follow Nandini. When Nandini stood King Dilip also stood up. When she walked he followed her. After she sat, then only he sat dow. After she drank water then only King Dilip used to drink water. In the evening when she came to the hermitage, he followed her too. Queen Sudikshina used to pray to that cow in morning and evening time. King slept on the ground near to Nandini. King Dilipa was serving Nandini with all devotion and care.
One month has elapsed serving cow, that day king was gazing at some beautiful flowers and in the meantime Nandini went ahead. Within a span of two three seconds he heard the sound of bawling cow. When he ran there he saw that one big lion has captured the cow. To kill the lion and to save the cow king lifted up his bow, but when he tried to take the arrow from his arrow case, his right hand got stuck to the case.
Lion in human voice told the confused king that “King I am no ordinary lion. I am devotee of Lord Shankar. Now you go away. I am hungry. With my luck she has come over here. I will satisfy my hunger by eating her.”
King Dilipa requested the lion “you are devotee of Lord Shankar, that’s why I bow you. With grace on me, you have given your introduction to me. Please do one more grace on me, leave the cow and eat me in return and satisfy your hunger.”
Lion counseled him a lot, but king Dilipa stuck over with his words. At last lion agree to eat him in return of cow. King stucked hands got apart from the arrow case. He put his bow and arrow case aside and sat in front of lion with his head down. Maharaj Dilip knew that the lion would attack him and tear him apart, but instead of this flowers start pouring on him from sky. Nandini in human Voice called him and said that there is no lion it was just the illusion created by me to testify you. Now you can drink my milk by milking it on the leaf. You will get the brave and good child.
King Dilipa got up. He bow in front of Kamdhenu and said that Mother on your milk first right is of your calf, after that its of Guruji. After going to hermitage I will take some sacred milk from the sage and will drink it. Seeing his devotion and religious love Cow Nandini was very happy on King Dilip. In the evening after returning to hermitage, Sage Vasishta gave king some milk to drink. King Dilipa was blessed with a brave child who was known as King Raghu (the ancestor of lord Ram).