What is the ruling when the specific item designated as the dower perishes after being specified for the wife?

Primary text

If the dower (mahr) is specified as the tailoring of a particular garment, and that garment perishes, the specification of the dower remains valid, and no equivalent dower (mahr al-mithl) is due. This is analogous to a measure of wheat specified as dower perishing before delivery. The husband must compensate the wife with the fair wage for the tailoring work performed, as the object of the contract was work, and its impossibility due to destruction necessitates compensation for the value of that work. This ruling is similar to cases where the teaching of a craft to a slave is specified as dower, and the slave dies before teaching occurs.