Is it valid to use stones previously thrown during Rami?
Chapter on the Description of Hajj
Al-Mughni
Book of Hajj
Primary text
Stones taken from what has already been thrown (al-marmi) do not fulfill the obligation. The evidence for this is that the Prophet, peace be upon him, took stones from elsewhere, commanding, 'Take your rituals from me.' Furthermore, if reuse were permissible, there would be no need to acquire and break new stones, and there is consensus against reuse. Ibn Abbas stated that what is picked up (from the throwing site) should be returned.
Supporting text
Shafi'i holds that it suffices because such stones are considered 'hasah' and fall under the general ruling.