Explanation

Mashar al-Haram means the 'Sacred Monument'

Masjid Mashar al-Haram (Arabic: مسجد مشعر الحرام) is a mosque situated in Muzdalifah 

Muzdalifah is the area where the Prophet ﷺ supplicated during his Farewell Pilgrimage.

Muzdalifah is located midway between Masjid al-Khayf in Mina and Masjid al-Namirah in Arafat.