Is it permissible for the buyer to take monetary compensation in lieu of receiving the stipulated personal service from the seller?
Chapter on Selling Assets and Fruits
Al-Mughni
Book of Sales
Primary text
If both parties mutually agree to substitute compensation for the service, it is likely permissible. This is because the service is a benefit for which compensation may be taken, even if it were not stipulated in the sale. Once the buyer possesses ownership of this benefit, it is lawful for him to take compensation for it, similar to a rental agreement, or as when the usufruct of bequests (*al-manafi' al-mawsu biha*) can be rented out to the heirs of the testator.
Supporting text
It is possible that taking compensation is not permissible. This view holds that because the stipulation is based on custom (*'adah*) and juristic preference (*istihsan*) due to necessity, taking compensation for it is not allowed, analogous to loans, where returning the exact equivalent in bread or flour, whether more or less, is permitted, but taking compensation for the excess amount permissible in the return is not allowed. Furthermore, taking compensation resembles receiving payment for an accustomed convenience (*marfiq mu'tad*) for which custom dictates forgiveness rather than demanding payment, thereby resembling benefits legally exempted (*al-manafi' al-mustathnah shar'an*). This is similar to the case where one sells land with existing crops, stipulating that the seller may remain until harvest; if the seller then demanded the crop (*qasil*) to utilize the land until the harvest time, he would not be entitled to that.