Sahih Bukhari Volume 003, Book 038, Hadith Number 500.

Narated By Ibn Ka'b bin Malik : From his father, We had some sheep which used to graze at Sala'. One of our slavegirls saw a sheep dying and she broke a stone and slaughtered the sheep with it. My father said to the people, "Don't eat it till I ask the Prophet about it (or till I send somebody to ask the Prophet)." So, he asked or sent somebody to ask the Prophet, and the Prophet permitted him to eat it. 'Ubaidullah (a sub-narrator) said, "I admire that girl, for though she was a slave-girl, she dared to slaughter the sheep."