“...an eye for an eye, a nose for a nose, an ear for an ear, a tooth for a tooth, and for wounds is legal retribution.” [al-Ma'idah 5:45] This is also analogous to the case where they jointly kill someone. If retaliation is due from all of them when they participate in killing, then it is all the more appropriate that retaliation be due from them when they participate in severing a limb. For a life is more inviolable, and retaliation for limbs is based upon retaliation for lives.

Likewise, if they inflict a wound that entails retaliation—according to the madhhab, every wound that reaches the bone—then retaliation is due from them. Thus, if they are ten people, we would inflict wounds upon ten heads for one head, and say: just as we kill ten persons for one person. Umar said: “Were the people of Sana'a to conspire together in killing him, I would kill them all for him.” (1)

His statement, “If a group cuts off a limb, or inflicts a wound requiring retaliation, then retaliation is due from all of them,” does not mention the ruling where they conspire together in it. The correct view is that, if they conspire together in it, it is as though they jointly participated in it. To conspire together means to agree upon it: for example, they say, “We want to cut off so-and-so’s hand.” One of them then says, “You sit in such-and-such a place, and you, the other one, sit in such-and-such a place, so that if anyone approaches, you inform me.” If they agree upon this, they have shared in the sin. Had these men not stood guard, the others would not have dared to carry out the severing; and they know that those others will cut this man. Therefore, if they conspire together in it, they have jointly participated in it. Umar said: “Were the people of Sana'a to conspire together in killing him, I would kill them all for him.”