Musannaf Ibn Abi Shayba 18:229

Abu Bakr narrated to us, he said: Muhammad bin Bakr narrated to us, from Ibn Jurayj, he said: I said to 'Ata': "Do you see, if the hand is cut off from the middle of the forearm?" He said: "Fifty [dinars/dirhams]." I said: "Then if something was cut from what remained after that?" He said: "A wound; I do not consider it to be anything else, unless there is a Sunnah regarding that."