Sahih Muslim Book 021, Hadith Number 4807.
Chapter : It is permissible to make use of things necessary for hunting and chasing but the use of small pebbles is disapproved.
'Abdullah b. Mughaffal reported that Allah's Messenger (may peace be upon him) prohibited throwing of pebbles. Ibn Ja'far reported (in the narration transmitted by him) that he (the Holy Prophet) said: It neither inflicts defeat to the enemy nor kills the game but breaks the tooth and puts the eye out. This hadith has been transmitted on the authority of Ibn Mahdi with a slight variation of wording.