Abu Dawud
Types Of Blood Wit
Book Number: 034 / Hadith Number: 4576
Narated By Abu Hurairah : The Apostle of Allah (may peace be upon him) said: No retaliation is payable for a wound caused by a dumb animal, for a mine, and for a well. On the treasure found buried in the land there is a fifth.
Abu Dawud said : A dumb animal means an animal which is free and has no tether, and there is no one (as a watchman) with it. It causes harm by day and not by night.