I came to the Messenger of Allah (ﷺ) at the place of halting, that is, al-Muzdalifah. I said: I have come from the mountains of Tayy. I fatigued my mount and fatigued myself. By Allah, I found no hill (on my way) but I halted there. Have I completed my hajj? The Messenger of Allah (ﷺ) said: Anyone who offers this prayer along with us and comes over to Arafat before it by night or day will complete his hajj and he may wash away the dirt (of his body).
The Rites of Hajj (Kitab Al-Manasik Wa'l-Hajj)
Sunan Abi Dawud - Hadith 1950
Hadith Text
"I came to the Messenger of Allah (ﷺ) at the place of halting, that is, al-Muzdalifah. I said: I have come from the mountains of Tayy. I fatigued my mount and fatigued myself. By Allah, I found no hill (on my way) but I halted there. Have I completed my hajj? The Messenger of Allah (ﷺ) said: Anyone who offers this prayer along with us and comes over to Arafat before it by night or day will complete his hajj and he may wash away the dirt (of his body)."
Commentary
This hadith establishes the fundamental condition for the validity of Hajj: standing at Arafat. The Prophet (ﷺ) clarifies that whoever joins the Maghrib and Isha prayers at Muzdalifah and was present at Arafat during any part of its time - day or night - has fulfilled the essential pillar of Hajj.
The companion's fatigue demonstrates his earnestness in performing the rites correctly. The Prophet's response emphasizes divine mercy, showing that Allah has made Hajj accessible and not burdensome. The permission to wash indicates that after fulfilling the essential rites, minor omissions or physical impurities do not invalidate the pilgrimage.
Scholars derive from this that standing at Arafat - even momentarily - during its prescribed time is the single most crucial rite of Hajj, without which the pilgrimage cannot be completed.