Can the injured party cut off the perpetrator's extra finger when Qisas is due?
Chapter on Retaliation (Qawad)
Al-Mughni
Book of Wounds
Primary text
If the extra digit is attached to one of the existing fingers, the injured party does not have the right to cut off that finger, because doing so would cause harm to the remaining, valid part of the extra digit itself.
Supporting text
There are two differing opinions regarding whether the injured party may cut off the four fingers themselves. Furthermore, if the extra digit is not attached to any of the four fingers, there are two opinions regarding whether the injured party may cut off all five digits (the four normal fingers plus the extra one). If the extra digit is fixed upon the uppermost segment (anmalah) of a finger, cutting it off is impermissible. If it arises from the middle or lower segment, there is one opinion that permits cutting off the segments above it. Under this same opinion, the injured party is entitled to the monetary compensation (arsh) for the segment that could not be severed, and this compensation is followed by the compensation equivalent to one-fifth of the palm.