Imam Reza (a.s.) was having a very stubborn horse which did
not allow anyone to come near it and ride it. Nobody dare to
ride it. Even if someone tried to ride it they feared being
thrown off or being squashed by it. There was a boy of seven
years who sought Imam (a.s.)’s permission to ride it and bring
the horse under control. Imam (a.s.) asked him whether he
could ride it and control it. He replied in affirmative and said:
“With the intention of riding the horse, I have recited hundred
salawaat on Mohammad (s.a.w.a.) and his progeny and I have
renewed my faith on you, the Ahle Bait (a.s.). After hearing
this, Imam (a.s.) granted him the permission. He not only rode
the horse but made it to run till the horse became tired and said
to Imam (a.s.): “O son of the Prophet (s.a.w.a.)! This boy has
troubled me, you save me.” Imam (a.s.) prayed for the horse.
After longtime, the boy came down from the horse. Imam (a.s.)
asked the boy to seek whatever he requires. The boy asked
Imam (a.s.) to pray for him. Imam (a.s.) said your prayers are
accepted.
Ref : Fazila e Salawaat