One day, while hunting, Janamejaya noticed the hermitage of a famous rishi called Srutasrava. This rishi had a son called Somasrava who was engaged in deep ascetic practices and devotion. 

Janamejaya bowed to the famous rishi, Srutasrava, with the desire to appoint the rishi’s son as his purohit. After bowing, Janamejaya said to the rishi, “O possessor of six attributes, please allow your son to be my purohit.”

The rishi answered: 

“O Janamejaya, my son who is accomplished in the Vedas and has the full force of my asceticism was born from the womb of a female snake that had drunk my vital fluid. He can help you obtain pardon for all offenses except for offenses committed against Lord Shiva. However, my son has a particular habit. If a brahmana asks him for something, he is sure to grant it to the brahmana. If you can accept and put up with this habit, then you may appoint him as your purohit.” 

Janamejaya accepted the condition and returned to Hastinapur with Somasrava. 

In Hastinapur, he informed his brothers that Somasrava was their purohit and that any demand made by him should be fulfilled without any questions.