´It was narrated that Urwah bin Mudarris said:` "I saw the Messenger of Allah stading in Al-Muzdalifah and he said: 'Whoever offers this prayer whith us here then stands with us and stood before that in Arafat by nightor by day, his Hajj is complete.
Explanation & Benefits
Hafiz Muhammad Ameen
(1) After performing the Fajr prayer, going near Mount Quzah or engaging in remembrance (adhkar) at any place in Muzdalifah is called wuquf (standing/staying). This wuquf will continue until shortly before sunrise. It is Sunnah to set out towards Mina before the sun rises. (Sahih al-Bukhari, Book of Hajj, Hadith: 1684).
(2) From the wording of the narration, it is understood that if a person returning from Arafat is so late that he cannot join the Imam of Hajj in Muzdalifah, his Hajj will not be valid. However, if a person has already performed wuquf in Arafat and arrives at Muzdalifah before dawn, but due to sleep or some other reason is late for the prayer and wuquf, his Hajj will be complete. In other words, it is necessary to perform the Fajr prayer in Muzdalifah, whether in congregation or individually. Remember! According to the correct opinion, performing the Fajr prayer in Muzdalifah is one of the pillars (arkan) of Hajj, the omission of which invalidates the Hajj. For further details, see: (al-Mawsu‘ah al-Fiqhiyyah al-Muyassarah, by Husayn al-‘Awda: 4/391).
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 3042