When claiming a fixed compensation (arsh) for an injury, what is the requirement?

Primary text

If the claim is for an injury with a known fixed compensation (arsh), such as a deep wound (mūḍiḥah) inflicted upon a free person, it is permissible to claim the injury without specifying the arsh, as the compensation is known. If the injury was inflicted upon a slave, or upon a free person where the arsh is not fixed, the amount of the arsh must be specified.