Abu al-Darda’ reported the Messenger of Allah (May peace be upon him) as saying : when a man cures anything, the curse goes up to heaven and the gates of heaven are locked against it. Then it comes down to the earth and its gates are locked against it. Then it goes right and left, and if it finds no place of entrance it returns to the thing which was cursed, and if it finds no place of entrance it returns to the thing which was cursed, and if it deserves what was said (it enters it), otherwise it returns to the one who uttered it. Abu Dawud said : Marwan b. Muhammad said: He is Rabah b. al-Walid who heard from him (nimran). He (Marwan b. Muhammad) said: Yahya b. Hussain was confused in it.