Disengaging out of Ihram
It was stated in Al Mausu’atul Fiqhiyyatul kuwaitiyyah that: The majority of scholars have agreed that shaving or shortening the hair of the head is an obligation of Hajj. This is the doctrine of the Hanafi, Maliki and Hanbali schools. Though the Al-Shafi’i holds the most popular opinion, which is the most correct in the school of thought, that it is a pillar of Hajj, they however differ in the amount that should be shaved or shortened. According to the Malikis and Hanbalis, it is obligatory to shave or shorten the entire head, while the Hanafis said: A quarter of the head is okay. According to the Shafi’i, it is alright to remove or shorten three strands of the hair out.
The majority are of the view that shaving or cutting the hair is not specific to a time or place, but the Sunnah is that he did it in the Haram during the days of slaughter. Abu Hanifa hereby maintains that shaving is specific to the days of slaughter and in the Haram area. If he breaks either of these two, he must make a slaughter for ransom, and his disengagement will take place by this shaving.
So it is permissible to disengage outside the Haram according to the opinion of those who think that it is permissible with the fact that he adheres to the Ihram clothing. This is because a person does not disengage from Umrah except after shaving or cutting (his hair) short.
His Eminence Sheikh Al-Uthaymeen, may God have mercy on him, says in The Guide to the Mistakes Made by the Pilgrims of Hajj and Umrah:
There are some people who when they finish doing sa’i and do not find someone to help them shave or cut their hair short, they then go to their houses. Thereafter, they disengage (from Ihram) and put on their casual clothes. After that, they now shave or shorten their hair. This act is a serious error. This is because a person does not disengage from the ihram of umrah except after shaving or cutting the hair short. As the Prophet, may Allah bless him and grant him peace, when commanding his companions in the farewell pilgrimage, that those who did not provide the sacrifice, should consider it as Umrah. He said: (Let him shorten and then disengage) Narrated by Al-Bukhari (1691) and Muslim (1229). This indicates that there is no disengagement except after shortening (the hair).
Based on this, when he finishes doing sa’i and does not find a barber or someone to shorten his hair, then he should remain in Ihraam until he shaves or shortens his hair.
It is not permissible for him to disengage before that, and if it is discovered that a person did this out of ignorance, (that is, he disengaged before he shaved or shortened his hair), thinking that this is permissible. There is no blame on him because of his ignorance, but he must, when he knows, take off his clothes and wear the Ihram garments. The reason is that it is not permissible to persist in exiting ihraam even though he knows that it was not permissible. After shaving or he shortens it, he can exit the ihram.