Strongest Thing in the World

This story is a small conversation between God and Angel......

There is a small conversation between God and an Angel who wanted to know about the strongest thing in the World :
Angel : Is there anything stronger than rocks?
God : Yes, Iron as it can break rock.
Angel : Anything stronger than iron?
God : Fire; for iron may be melted in fire.
Angel : Anything stronger than fire?
God : Yes, water; for fire is extinguished by water.
Angel : Anything stronger than water?
God : Yes, wind; for wind may scatter water.
Angel : Anything stronger than wind?
God : Sympathy is stronger. And nothing can be there that is stronger than the compassionate heart.