Ikrimah (may Allah have mercy on him) narrates from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that he was asked about slaughtering with a piece of wood, and he said: Everything that cuts the veins and makes the blood flow, but not something that does not make the blood flow.
And Abu Ubayd says: Tathrid means an animal that is slaughtered with something that does not make the blood flow; "ma afra al-awdaj" means "something that cuts the veins and makes the blood flow." Abu Ubayd says: Some people say its meaning is "eat," but this is not correct; rather, its meaning is that whatever cuts the veins, wood or stone, will be counted as a valid slaughter.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19151