On a journey to Kabul, Zal heard of Rudabeh, daughter of King Mehrab, said to be more beautiful than the moon. Rudabeh had also heard of the brave Zal, and the two fell in love before they had ever met. But Mehrab was descended from Zahhak, and such a match seemed impossible.
With the help of her maids they met in secret. Rudabeh let down her long hair from her tower so that Zal could climb it. But Zal did not want to hurt her: he kissed her hair, threw a rope up instead and climbed to her. They swore eternal loyalty. When their fathers and King Manuchehr learned of it, war threatened; only when the astrologers announced that this marriage would bring forth Iran’s greatest hero did everyone give their blessing.
The birth of their son was so difficult that Rudabeh almost died. Zal burned a feather of the Simorgh. The bird appeared and explained how to bring the child out of the mother’s body with a cut and heal the wound with herbs. So Rostam came into the world, as big as a one-year-old. Rudabeh cried “Rastam”, I am delivered, and that is said to be where his name comes from.