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.
Sahih Muslim Book 34, Hadith 81
← Previous Hadith This hadith has been transmitted on the authority of Kahmas.

Sahih Muslim Book 34, Hadith 80 Next Hadith → It does not catch the game, nor does it inflict defeat on the enemy, but breaks the tooth and puts the eye out. He (the near one of Abdullah b. Mughadal) again repeated it (the act of throwing of pebbles) whereupon he said: I narrate to you that Allah's Messenger (may peace be upon hish) disliked and prohibited throwing of pebbles, but I see you again throwing pebbles; I (would therefore) not speak with you.

Sahih Muslim Book 34, Hadith 82