These are some of the mistakes that are made when entering the Haram. They may be explained as follows:
Some people think that it is essential for the pilgrim doing Hajj or ‘Umrah to enter through a specific gate of al-Masjid al-Haraam. So some people think that if they are doing ‘Umrah they must enter through the gate called Baab al-‘Umrah, and that this is essential and is prescribed in sharee’ah. Others think that they must enter through Baab al-Salaam, and that entering through any other gate is a sin or is makrooh. There is no basis for this. The pilgrim doing Hajj or ‘Umrah may enter through any gate, but when he enters the mosque he should enter with his right foot first and say what is narrated for entering all mosques, and send blessings upon the Prophet (peace and blessings of Allaah be upon him), and say, “Allaahumma aghfir li dhunoobi waftah li abwaab rahmatika (O Allaah forgive me and open to me the doors of Your Mercy).” Narrated by Muslim, 713.
Some people have invented specific du’aa’s for when one enters the Mosque and sees the Ka’bah, and have introduced du’aa’s that were not narrated from the Prophet (peace and blessings of Allaah be upon him). This is a kind of bid’ah (innovation). Worshipping Allaah with words, actions or beliefs that were not known to the Prophet (peace and blessings of Allaah be upon him) and his companions is innovation and misguidance which the Messenger of Allaah (peace and blessings of Allaah be upon him) warned us against.
Some people - even those who are not doing Hajj – mistakenly believe that the greeting for al-Masjid al-Haraam is tawaaf, in the sense that it is Sunnah for everyone who enters al-Masjid al-Haraam to do tawaaf, basing that on the view of some of the fuqaha’ that the Sunnah when entering al-Masjid al-Haraam is to do tawaaf. In fact this is not the case. Al-Masjid al-Haraam is like all other mosques, concerning which the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “When any one of you enters the mosque, let him not sit down until he has prayed two rak’ahs.” Narrated by al-Bukhaari, 444; Muslim, 714.
But if you enter al-Masjid al-Haraam to do tawaaf other than the tawaaf of Hajj or ‘Umrah, or for a voluntary tawaaf, then it is permissible for you to do tawaaf without praying two rak’ahs first. This is what is meant by saying that the greeting for al-Masjid al-Haraam is tawaaf. Based on this, if you enter with no intention to do tawaaf, rather you are waiting for the prayer or you are coming to attend a lesson etc, then al-Masjid al-Haraam is like any other mosque and it is Sunnah to pray two rak’ahs before you sit down, because the Prophet (peace and blessings of Allaah be upon him) enjoined that.