Musannaf Ibn Abi Shayba 18:210

Abu Bakr narrated to us, he said: Muhammad bin Bakr narrated to us, from Ibn Jurayj, from ‘Amr bin Shu’ayb, he said: Abu Bakr al-Siddiq ruled regarding the tongue: If it is cut off from its root, the blood money (diyah) is due. And if its tip is cut off, but its owner can still speak, then half of the blood money is due for it.