Is it obligatory to remain at Mount Arafat until sunset after arriving there during the day, and what is the penalty for departing before sunset?
Chapter on Ransom (Fidyah) and Penalty for Hunting
Al-Mughni
Book of Hajj
Primary text
It is obligatory for one who stands at Mount Arafat during the day to remain there until sunset to combine both day and night for the standing. If one departs before sunset and does not return until after sunset, a sacrifice (Dam) is obligatory. The evidence is that the Prophet, peace be upon him, stood until the sun set without dispute, and the command was given: 'Take your rites from me.' If this is neglected, a penalty is incumbent because a fundamental pillar (Rukn) was not observed in the prescribed manner.
Supporting text
Al-Shafi'i holds that remaining until sunset is not obligatory, and no penalty is due if one leaves before sunset, arguing that fulfilling a portion of the standing sufficient for obligation is adequate. However, if one only arrives during the night, it suffices, and no penalty is due because standing during the day cannot be fulfilled.