How should the procedure for execution of Qisas (retaliation) for a Mūḍiḥah wound (a gash exposing the bone) be performed when the perpetrator's head is used as the measurement standard?

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When seeking full execution of Qisas for a Mūḍiḥah or similar wound, the hair must be shaved from the site of the injury on the injured party's head. The length and width of the original wound are measured using a stick or thread on the injured party's head and marked on the perpetrator's head using soot or another marking substance. An iron tool, matching the width of the original wound, is used to measure the length by drawing it from the beginning to the end of the wound's marked area. The measurement must only account for length and width, not depth, as the depth limit is the bone, and accounting for depth would lead to impossibility due to variations in flesh thickness among people. This is analogous to executing Qisas in a limb where the size difference (smallness or largeness) is overlooked, but length and width are observed because they are measurable. If the perpetrator's head is the same size as the injured party's, the exact measure of the wound is executed. If the perpetrator's head is smaller but can contain the measurement, the Qisas is executed provided the entire perpetrator's head is used in the measurement, even if the executed portion constitutes only part of the original wound on the injured party. The execution is not barred if the executed portion exceeds the size of the corresponding spot on the perpetrator's head, as the entire head is considered the subject of retribution. If the wound size exceeds the perpetrator's entire head, the wound is executed across the entirety of the perpetrator's head, but the execution cannot extend to the forehead or the nape of the neck, as this would constitute retaliation in a different organ than the one injured.