The mas’aa (place of saa’i) is not part of al-Masjid al-Haraam
Question

                Is the mas’aa (place of saa’i) part of al-Masjid al-Haraam? Can a menstruating woman approach it? Does a person who enters the mas’aa have to pray tahiyyat al-masjid (two rak’ahs to greet the mosque)?.
Praise be to Allah.Shaykh Muhammad ibn ‘Uthaymeen (may Allaah 
    have mercy on him) said:
 “It seems that the Mas’aa is not part of the 
    Mosque, hence they built a wall to separate the two, but it is a low wall. Undoubtedly this is better for people, because if it were to be 
    incorporated into the Mosque and made a part of it, a woman whose period began between tawaaf and saa’i would not be able to do saa’i.
 What I say is that if a woman’s period 
    begins after tawaaf and before saa’i, she should still do saa’i, because the Mas’aa is not considered to be part of the Mosque.
 With regard to tahiyyat al-masjid (greeting 
    the mosque), it may be said that if a person does saa’i after tawaaf and then goes back to the Mosque, then he should pray tahiyyat al-masjid, but 
    if he does not do it there is no blame on him. It is better to make the most of this opportunity and pray these two rak’ahs, because of the virtue 
    of praying in this place.