The story of King Janasruthi is told in the Chandogya Upanishad chapter 4. He was a philanthropist and philosopher.

Janasruti was an ideal King. He ruled the country so well that none starved in his country. One day he heard the name Raikva while two birds arguing on the best man on earth. King sent his messengers to find the person name Raikva, who could be more learned and more philanthropic than him. But none could find such a man. King was so much careful about improving himself that he set out himself to find the most ideal person on the world. At last he found a man called Raikva, a poor cart driver in a remote village.

The King introduced himself, But Raikva did not cared little about it. King offered him many gits and invited him to palace. Raikva refused, and king returned to the palace,

King discussed the matter with his kinsman. But none could find any qualities better than their king in this poor man. King studied the poor man and found he is holding some secret spiritual knowledge that could be the reason the birds might have praised him. King again left the palace for Raikva, this time with his family and served the poor man and told his desire to learn from him. The king then offered many other things to tempt Raikwa. Raikwa didn't even react to that. Finally the king gave in completely and said to Raikwa, “I will give you whatever you ask for, please teach me. Raikva looked up and said: “You have brought me many things, but they do not make me speak. Wealth and fame is perishable. Your eagerness to know is the best quality of a student, so I will teach you whatever I know.

Raikwa said: ”Air swallows everything. When the sun sets, when the moon sets, it disappears into thin air. When water dries up, it disappears into the air. Air swallows them all. It is the worship of the forces of nature, and they ask nothing in return for their great deeds”

As far as I understand, speech, eyes, ears and mind are all functioning in a person due to Prana. Nothing works without soul. Prana swallows all these. Air and Prana are all consuming”. Raikwa went on to say, "There are many powers in this creation who are worshiped as gods. There is the wind that sweeps everything away. Whatever comes in contact with fire, it burns. There is also the breath of life that animates a being. It creates and sustains the universe. Thus, the entire creation is a complex instrument that performs its work under the direction of the soul.

Don’t be proud or arrogant in the alms you distribute. Maharajan! you may go back to the palace. Don't be proud of giving. Give generously, give freely without condition, never be selfish. Don't aim for fame. Nothing was yours to give, you were just a means to distribute things to others. God has given you a chance. He who sees this truth becomes a philosopher, He lacks nothing, He is only a doer of things. He enjoys the universe in its uniqueness, He is not different from the universe; He the Universe, or in another words all is Brahman.”

The king was extremely pleased with these words of wisdom from Raikwa. Before going back, the king gave his own daughter in marriage to Raikwa. So also, a thousand cattle, many gold coins and a chariots.