The Sunnah indicates that the one who wants to offer a sacrifice must refrain from taking anything from his hair, nails or skin from the first day of Dhu’l-Hijjah until he offers his sacrifice because the Prophet (peace and blessings of Allaah be upon him) said: “When you see the new moon of Dhu’l-Hijjah, if any one of you wants to offer a sacrifice, let him not remove anything from his hair or nails until he has offered his sacrifice.” According to another report: “Let him not touch any part of his hair or nails.” (Reported by Muslim with four isnaads, 13/146).
This command implies obligation and the prohibition implies that it is forbidden, according to the most correct opinion, because these are absolutes with no exceptions. If a person deliberately takes something (from his hair or nails), he must seek the forgiveness of Allaah, but he does not have to pay any fidyah (penalty), and his qurban is still valid. Whoever needs to remove some of his hair or nails because leaving it will cause him harm, such as a torn nail or a wound in a site covered by hair, should remove it, and there is no sin on him if he does so. This is not more serious than the muhrim (person in ihraam for Hajj or ‘Umrah) who is allowed to shave if not doing so will cause him harm. There is nothing wrong with men and women washing their hair during the first ten days of Dhu’l-Hijjah, because the Prophet (peace and blessings of Allaah be upon him) only forbade removing hair, and because the muhrim is allowed to wash his head.
The wisdom behind the prohibition on removing hair and nails is because the one who is going to offer a sacrifice is like the one who is in ihraam for Hajj and ‘Umrah with regard to some rituals, which is the offering of a sacrifice in order to draw closer to Allaah. Thus some of the rulings of ihraam apply to the one who wants to offer a sacrifice, so he should not touch his hair and nails until he has slaughtered his sacrifice, in the hope that Allaah will release him from the fire of Hell. And Allaah knows best.
If a person removes some of his hair and nails during the first ten days of Dhu’l-Hijjah because he is not planning to offer a sacrifice, then he decides to sacrifice, he should refrain from cutting his hair or nails from the moment he takes the decision.
There are some women who delegate their brothers or sons to do the sacrifice on their behalf so that they can cut their hair during the first ten days of Dhu’l-Hijjah. This is not correct, because the ruling applies to the one who is making the sacrifice, whether he or she delegates someone else to do the actual slaughter or not. The prohibition does not apply to the person appointed, it applies to the person who wants to offer a sacrifice on behalf of himself, as is indicated by the hadeeth. As for the person who is doing the sacrifice on behalf of another, whether because of a will or because he has been delegated to do so, the prohibition does not apply to him.
It is apparent that this prohibition applies to the one who is offering the sacrifice, and does not extend to his wife or children unless one of them is offering a sacrifice on his or her own behalf. The Prophet (peace and blessings of Allaah be upon him) used to sacrifice on behalf of the family of Muhammad, and it was not reported that he forbade them to remove anything of their hair or nails.
Whoever is planning to offer a sacrifice, then decides to go for Hajj, should not remove anything of his hair or nails when he wants to enter ihraam, because this is Sunnah only when there is a need for it. But if he is doing Hajj “tamattu’” [where one performs ‘Umrah, then ends ihraam and enters a new state of ihraam for Hajj], he should shorten his hair when he finishes ‘Umrah because that is part of the ritual.
The things that are forbidden for the person who wants to offer a sacrifice are reported in the hadeeth quoted above. It is not forbidden for him to wear perfume or to have intercourse with his wife or to wear sewn garments and so on.