In the Ikshvaku dynasty – Ayodhya was once ruled by king Dilip. He was a scholar in all arts and sciences, a great warrior, and a benevolent ruler. His fame and valour were known in all the 3 worlds.
Raja Dilip and his queen, Sudakshina Devi, had only one worry. They were childless and yearned for a child. They performed Lord Brahma’s puja and went to visit their kulguru, rishi Vashishth, and asked him the reason for their not having a child.
Vashishth, with his divvy drishti, realized the reason. He told Samrat Dilip “O Raja! Once you visited Indra dev in swargalok. Hurrying to meet your queen, you did not see the celestial gomaata Kamdhenu on your way back. You forgot your dharma and did not stop to pay your respects to her. She cursed you to be childless until you please her santaan”. So you need to pray to her child, Nandini, to grant you a son”.
On rishi Vashishth’s instructions, Dilip and his queen stayed at Vashishth’s ashram to observe the vrat. Every morning, Sudakshina Devi would offer prayers to the cow and Raja Dilip would follow it into the forest and stand guard, till its return back to the ashram in the evening.
This continued for 21 days. On the 22nd day, gomata Nandini decided to test Dilip’s bhakti. She went further than usual and entered a cave in the forest. Raja Dilip, following her, heard a lion’s roar and Nandini’s cry. He rushed inside and saw that Nandini was under the clutches of a lion. Raja Dilip raised his hand to take his arrow and shoot the lion. To his surprise, his hand stood paralysed on his quiver, and he couldn’t move. The lion then said “Samrat Dilip! I’m not an ordinary lion. I’m Kumbhodar, Lord Shiv’s sevak. He uses my back as a stool to sit on his bull, Nandi. He granted me to this form to protect this favourite grove of Mata Parvati. Anyone who enters this will become my prey. So it is useless to try and protect this cow. Return back to your ashram”.
Raja Dilip said “O divine beast! It is useless for me to try to defeat someone protected by Mahadev. This divine cow is entrusted to my protection by rishi Vashishth. Its calf is eagerly waiting for her mother’s return. It is a duty of a king to protect the subjects under his care. So I beg you to let mata Nandini go”.
The lion refused. The king then said “O lion king! In that case, please eat me instead of the cow”. The lion agreed. Raja Dilip’s arm came free. He willingly offered himself to the lion. But, amazingly, he was showered with flowers. Mata Nandini then spoke “Arise my son! I created this illusion to test you. By rishi Vashishth’s grace, even Yamraj cannot touch me. I am pleased with your devotion. Ask me anything you want”.
The king was overjoyed. He bowed with reverence and said “O divine mother! We need a son worthy of my race”. “So be it” said Nandini.
After returning back to the ashram, the royal couple paid their respects to the divine cow and rishi Vashishth, and came back to Ayodhya. In due course, a son was born to them, who was named Raghu, on whose name the dynasty came to be known as Raghuvansh.
Source – Raghuvamsam – Mahakavi Kalidas