If we say that what lies beyond the explicit text is to be analogically compared with what is established by the text, then we need to establish that the original case and the derived case share the same effective cause. So what effective cause enables us to extend the ruling from the hair of the head to the hair of the rest of the body?

They say: The effective cause is comfort and grooming, because shaving the hair of the head brings cleanliness. The evidence for this, they say, is that the more dirt accumulates on the head, the more lice, odour, and discomfort it contains. But is this conceded? Let us consider: is the person in ihram prohibited from comfort and grooming?

The answer is that he is not prohibited from enjoying good food; he may eat whatever wholesome foods he wishes. Nor is he prohibited from comfort in clothing; he may wear whatever garments permitted in ihram he wishes. Nor is he prohibited from comfort through removing dirt: he may bathe and remove dirt. So who can claim that the effective cause behind prohibiting the shaving of the head is comfort and grooming, such that the ruling may be extended on this basis?!

Rather, the apparent effective cause is that if the person in ihram shaves his head, he thereby forgoes a prescribed rite: shaving or trimming the hair at the completion of the ‘umrah, and after stoning Jamrat al-‘Aqabah during Hajj. If he shaves his head during ihram and then reaches Mecca within a few hours, as is the case in our time, what is he then to do?!

Thus, the effective cause is the forfeiture of one of the rites of pilgrimage—namely, shaving or trimming the hair. Upon reflection, this reasoning is more compelling than the reasoning that it is prohibited for the sake of comfort and grooming. Accordingly, only shaving the head is prohibited.

They also said: The basic presumption regarding the hair a person removes is permissibility. Therefore, we do not forbid anyone from removing any of his hair except on the basis of evidence. This is the stronger view.