Is the ritual throwing valid if the stone lands on a hard surface outside the designated area, rolls onto a person's garment, and then lands correctly?
Chapter on the Description of Hajj
Al-Mughni
Book of Hajj
Primary text
If a stone lands on a hard surface outside the designated area, rolls onto a person's garment, and then lands in the designated area, the act is valid because the stone's final arrival in the designated area resulted from the thrower's action.
Supporting text
If the person whose garment the stone landed on then shakes the stone off, causing it to land in the designated area, there is a difference of opinion. Ahmad holds that it is valid because the person ultimately released the stone. Ibn 'Aqil holds it is invalid because the final landing in the designated area resulted from the action of the second person, similar to if that second person had picked up the stone and thrown it.