The Prophet (peace and blessings of Allah be on him) said,
“Although I am staying here, you may stay anywhere throughout Muzdalifah.” [Muslim]
Mashaer Al-Haram (The Sacred Monument) is also mentioned in the Quran in Surah Baqarah, when Allah (SWT) says: “When you leave Arafat, then remember Allah at the Mash’arul Haram”, referring to Muzdalifah.
Muzdalifah stretches from the Valley of Muhassar to the mountains of Ma’zamayn, covering an area of 12.25 square kilometres. Hajj pilgrims arrive at Muzdalifah from Arafat after sunset on the second day of Hajj i.e. 9th Dhul Hijjah.
The Prophet (PBUH) performed the Maghrib and Isha Salah together at Muzdalifah during the farewell Hajj and stayed at the spot where Masjid Mash’arul Haram currently stands.
Hajj pilgrims also perform Maghrib and Isha together in Muzdalifah at Isha time, which is a Waajib act in Hajj. Wuqoof (stay) of Muzdalifah is also Waajib and pilgrims must spend some portion of their time in Muzdalifah. However, it is best to stay the night. Pebbles for pelting the Jamarat are also collected from Muzdalifah.