Praise be to Allah.
Removing hair from the head is one of the things that are prohibited when in ihram, regardless of whatever means is used to remove it, whether it is by shaving, cutting, plucking, scratching and so on, because Allah, may He be glorified and exalted, says (interpretation of the meaning): “and do not shave your heads until the Hady [sacrificial animal] reaches the place of sacrifice” [al-Baqarah 2:196].
The scholars are unanimously agreed on this ruling, as they are unanimously agreed that combing the hair is prohibited if it is certain that some of it will fall out because of combing it.
It says in al-Mawsoo‘ah al-Fiqhiyyah (11/179):
If the pilgrim in ihram is certain that some hair will fall out as a result of combing it, then there is no difference of opinion among the fuqaha’ that combing it is haraam in that case. End quote.
But if his hair will not fall out as a result of combing it, the scholars differed, and there are three opinions:
1.The first view is that it is allowed and permissible. This is the view of Ibn Hazm az-Zaahiri, who said in al-Muhalla (5/186): With regard to undoing the hair (if it is braided) and combing the hair, that is not makrooh when in ihram; rather it is permissible in all cases. End quote.
Some of the scholars quoted as evidence for this opinion the hadeeth narrated by al-Bukhaari (316) and Muslim (1211) from ‘Aa’ishah (may Allah be pleased with her) who said: I entered ihram with the Messenger of Allah (blessings and peace of Allah be upon him) for the Farewell Pilgrimage, and I was one of those who did tamattu‘ (‘umrah followed by Hajj, exiting ihram in between), and I did not bring a sacrificial animal with me. She said that she got her menses, and did not become pure until the night before ‘Arafah began. She said: O Messenger of Allah, this is the night before ‘Arafah and I had intended to do tamattu‘ but I have not done ‘umrah yet. The Messenger of Allah (blessings and peace of Allah be upon him) said to her: “Undo your hair and comb it, and enter ihraam for Hajj, and leave ‘Umrah for now.”
They said: The Messenger of Allah (blessings and peace of Allah be upon him) gave ‘Aa’ishah permission to comb her hair even though she was in ihram; he only told her to do ghusl for entering ihram for Hajj, because her ihram had originally been for ‘umrah.
Ash-Shawkaani said in Nayl al-Awtaar (5/94):
The word “comb your hair” indicates that there is nothing makrooh in the pilgrim in ihram combing his hair, although it was also said that it is makrooh.
An-Nawawi said: The scholars interpreted this action of ‘Aa’ishah’s as indicating that she was excused, because she had an ailment in her scalp, so he permitted her to comb her hair just as he permitted Ka‘b ibn ‘Ajrah to shave his head, because of an ailment. And it was said that what is meant by combing here does not really refer to actual combing; rather it refers to running the fingers through the hair when doing ghusl for ihram of Hajj, especially since she had stuck her hair together (talbeed - whereby the pilgrim uses some sticky substance to stick his or her hair together in order to keep it orderly and protect against lice ), as is Sunnah and as the Prophet (blessings and peace of Allah be upon him) did, so it was not correct to wash it except by causing the water to reach all parts of the hair, which required undoing it. End quote.
2.The second view is that it is haraam. This is the view of some of the Hanafis, who quoted as evidence the hadeeth of Ibn ‘Umar (may Allah be pleased with him) who said: A man went to the Prophet (blessings and peace of Allah be upon him) who said: Who is the pilgrim, O Messenger of Allah? He said: The one who is dishevelled and unkempt.” Narrated by at-Tirmidhi (2998)
They said: What is meant by dishevelled is that the pilgrim’s hair is disorderly and out of place, and is not kept together by combing, applying oil, covering it, and so on.
See: al-Ikhtiyaar li Ta‘leel al-Mukhtaar (1/143); al-Mawsoo‘ah al-Fiqhiyyah (11/179)
But the hadeeth is da‘eef. Al-Albaani said concerning it in Da‘eef Sunan at-Tirmidhi: (It is da‘eef jiddan (very weak).
3.The third view is that it is makrooh, because it exposes one to the risk of committing one of the acts that are prohibited whilst in the state of ihram. This is the view of the Shaafa‘is and Hanbalis.
An-Nawawi said in al-Majmoo‘ (7/374): It is makrooh (for the pilgrim in ihram) to shave his hair and beard, because that is more likely to make hair fall out. End quote.
Al-Bahooti al-Hanbali said in Kashshaaf al-Qinaa‘ (2/424):
The muhrim (pilgrim in ihram) may wash his head and body. That was done by ‘Umar and his son, and a concession allowing that was granted by ‘Ali and Jaabir, without combing the hair, because combing may lead to hair breaking off. End quote.
See also al-Insaaf (3/460)
The final view, that it is makrooh, is the most fair opinion, so the Muslim should be keen to do his acts of worship and not expose them to that which may undermine them, even if it is unlikely.
Shaykh Ibn ‘Uthaymeen said in Fataawa Noor ‘ala ad-Darb (Fataawa al-Hajj wa’l-Jihad/Bab Mahzooraat al-Ihraam):
The pilgrim in ihram should not comb his hair, because what the muhrim should be is dishevelled and dusty, but there is nothing wrong with him washing his head. As for combing his hair, it brings the risk of causing hair to fall out.
If a woman or a man combs her or his hair and sees some hairs on the comb, and does not know whether they fell out because of combing or they had already fallen out (but were still on his head), she or he does not have to offer a fidyah in this case, because of the possibility that the hair had already fallen out by itself, and the individual does not have to offer a fidyah in the case of mere uncertainty or possibility. This was stated by an-Nawawi (may Allah have mercy on him) in al-Majmoo‘ (7/262) and something similar was stated in Kashshaaf al-Qinaa‘ (2/423).
And Allah knows best.