A king wanted to protect his kingdom from natural disasters and planned a sacrifice.
The priest advised human sacrifice to be more powerful than animal sacrifice. So the king bought the middle son, Sunashepa, from a poor couple. Sunashepa was happy that his parents had become wealthy through him and went with a happy heart.
On the way he received a spell from a sage. This he spoke during the sacrifice, and the God of fire and the God of the waters appeared to explain that they would never visit the kingdom.
Sunashepa then became a great sage.
A similar story is the one of Shunahshefa.
Bhasa composed the story – Madhyama Vyayoga.
https://navankura.wordpress.com/125-2/