Passing through the Hijr when doing Tawaaf
Question

                Some people enter through the gate of the Hijr when doing tawaaf, and they do not complete tawaaf from outside the Hijr, especially when it is crowded. Is their tawaaf valid?.
Praise be to Allah.
    Shaykh Muhammad ibn ‘Uthaymeen (may Allaah have mercy on him) 
    said: This is a very serious mistake, when some people enter through the 
    gate of the Hijr when doing tawaaf and exit through the other gate when it 
    is crowded, thinking that this is easier. It is a serious mistake because 
    the one who does that is not considered to be doing tawaaf around the 
    Ka’bah. Allaah says (interpretation of the meaning): 

    “and circumambulate the Ancient House (the Ka‘bah at 
    Makkah)”

    [al-Hajj 22:29]

    The Prophet  (peace and blessings of Allaah be upon him) 
    circumambulated the House from outside the Hijr. If a person circumambulates 
    the Ka’bah going inside the Hijr, he is not regarded as having 
    circumambulated the House, so his tawaaf is invalid. This is a serious 
    matter, especially since tawaaf is a pillar (essential part) of both Hajj 
    and ‘Umrah. The answer to that is that we should explain to the pilgrims 
    that tawaaf is not valid unless it encompasses the entire Ka’bah, including 
    the Hijr. 

    Calling the Hijr “Hijr Ismaa’eel” 

    I would like to take this opportunity to point out that many 
    people call the Hijr “Hijr Ismaa’eel”, but in fact Ismaa’eel had nothing to 
    do with it and it is not his Hijr. Rather this Hijr came into being when 
    Quraysh ran short of cash, when they wanted to rebuild the Ka’bah, and they 
    did not have enough resources to build the Ka’bah on the foundations of 
    Ibraaheem, so they left this side out of it, and it was called hateem 
    and hijr; so Ismaa’eel knew nothing of it and had nothing to do with 
    it. 

    There are some people who do not make sure they keep the 
    Ka’bah on their left, so you see them doing tawaaf with their women folk, 
    and they hold hands with their brothers or friends to protect the women, so 
    you see them doing tawaaf with their back towards the Ka’bah, and his 
    brother or friend doing tawaaf facing towards the Ka’bah. This is also a 
    serious mistake, because the scholars say: One of the conditions of tawaaf 
    being valid is that the Ka’bah should be to one's left, and if you have you 
    back towards it, or face it, or walk with it to your right, then this tawaaf 
    is not valid. 

    What people should do is to pay attention to this matter, and 
    strive to make sure the Ka’bah is to their left throughout tawaaf. 

    There are some people who put their backs to the Ka'bah or 
    face it for a few steps because of the crowding. This is also a mistake. 
    People should be on the safe side with regard to religious matters, and 
    acknowledge the boundaries set by Allaah with regard to worship and avoid 
    mistakes, so that they will worship Allaah with knowledge. 
Does it not astonish you 
    that if a man wants to travel to a land that he does not know, he does not 
    travel until he has asked about it and tried to find out the easiest way to 
    get there, so that he can reach it comfortably and with ease, without 
    getting lost, but when it comes to matters of religion, many people – 
    unfortunately – start their worship and do not know the limits set by 
    Allaah. This is a shortcoming, and indeed is negligence. We ask Allaah to 
    guide us and our Muslim brothers, and to make us among those who know the 
    limits that Allaah revealed to His Messenger.