What is required of one who has undergone hair transplantation and wishes to perform Umrah, and should he shorten the newly transplanted hair, or only the old hair? And is it a condition that the hair lengths be equal when shortening?

Scholars differ regarding the sufficient amount for shaving (Halaq) or shortening (Taqseer) the hair. The most preponderant opinion among scholars is that of the Malikis and Hanbalis, which states that shaving only part of the head is not sufficient; rather, the entire head must be shaved or shortened.

However, it is not necessary to shorten the hair from the entire head with equal length. It is sufficient to take from the entire head, even if the lengths vary. If it is difficult to take from the entire head, and it is possible to shorten from "most of the head" such that the unshortened part is the minority, then there is no harm.

If taking from most of the head is difficult, or if it harms hair transplants, then it is sufficient to shave what can be shaved without harm or undue difficulty. This is based on the opinion of those who say that shortening part of the head is sufficient, which is the view of the Hanafis and Shafi'is.

Although the relied-upon opinion in fatwa is to generalize to the entire head, it is permissible to adopt the other opinion in cases of excessive hardship and difficulty beyond the usual hardship. This falls under the category of concession (rukhsa) that applies in matters of permissible scholarly disagreement, as Taj al-Din al-Subki said: "It is permissible for the ignorant to follow [an opinion], and to adopt a concession from the sayings of scholars, at times, when there is a pressing need, without constantly seeking out concessions."

If the mukallaf (person responsible) has the means and can slaughter a sheep, in deference to the opinion of those who obligate generalizing to the entire head, then that is good. If he cannot find one, then there is nothing upon him.