It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that Sayyiduna Ka'b bin Malik (may Allah be pleased with him) had a slave girl who used to graze his goats at "Sala'", and one of those goats was about to die, so the slave girl took a sharp-edged stone and slaughtered the goat with it. The Prophet (peace and blessings of Allah be upon him) permitted them to eat it.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5512