Abu Bakr al-Hanfi عبد الكبير بن عبد المجيد- أبو بكر الحنفي · The Book on Hunting

"The Prophet (ﷺ) came to Al-Madinah and they were in the habit of cutting the humps off of the camels and cutting the buttocks from the sheep. He said: 'Whatever is cut from an animal while it is alive, then it is dead flesh.'"