Why does Ferdowsi give Esfandyar the challenge of The Seven Stages?

Ferdowsi gives Esfandyar the challenge of The Seven Stages as a test of his character, bravery, and determination. It serves as a way to showcase Esfandyar's virtues and capabilities as a hero in the Shahnameh. By completing the challenge, Esfandyar proves himself worthy of the responsibilities and leadership that come with being a great warrior.