Before he became a Sage, Vishwamitra was a king named Kaushika. He was a powerful and arrogant king. The story of the transformation of Kaushika to Vishwamitra symbolically shows the greatness of spirituality over wealth and power.
One day King Kaushika and his troops reached the ashram of Sage Vasishta. The king and his soldiers were warmly welcomed by Sage Vasishta.
Sage Vasishta invited them for food. The arrogant king doubted how a poor sage could feed him and his army.
To his surprise the king and his soldiers were treated to the best foods. So much food and different varieties of food was served to all the people.
King wanted to know how a poor Sage could prepare such huge amount of food in a short span of time.
The Sage Vasishta revealed that he was the owner of the divine cow Kamadhenu – the holy cow was a wish fulfilling cow.
Kaushika now wanted the cow as he felt the animal would be more useful to a king than to a sage.
Sage Vasishta said that the divine cow had come on its own to the ashram and if it wishes to go then he can take it.
Kamadhenu was not ready to leave the ashram.
When the king resorted to force Sage Vasishta objected to it.
Kaushika then decided to attack the sage. The sage then simply took a stick and planted before him. The stick prevented all the attacks of Kaushika and his soldiers.
The king and his soldiers had to return empty handed.
For next few days the king was in deep thought. He began to detest his kingly powers and authority. He thought what use it is if his powers could not defeat a poor sage.
The king realized the greatness of spirituality over physical strength and power.
He gave his throne to his son and went to forest and started performing austerities.
Kaushika then became a Brahmarishi after several years and he was called Vishwamitra – friend of the universe.