Wuquf at 'Arafat
Wuquf at 'Arafat (staying in the land of 'Arafat) is the second obligation of hajj. 'Arafat is a well-known place near the holy city of Mecca. Wuquf means being present in the land of 'Arafat, no matter whether a person is riding, walking, standing, or lying. Wuquf (staying) in the land of 'Arafat is an acts of worship. It should be accompanied by intention.
Wuquf
It is based on caution that a person should be in the land of 'Arafat from time of shar'i noon of the 9th of Dhu l-Hijja until the time for maghrib prayer. It is not remote to say one may delay the wuquf a little bit after shar'i noon, the time enough to perform zuhr and 'asr prayers together with their preliminaries.
The above mentioned wuquf is obligatory from 'noon' to the maghrib prayer. Therefore, even if a person stays there for a part of the mentioned period, his wuquf is correct. It is forbidden to exit 'Arafat before shar'i sunset. Therefore, if a person exits this place before sunset intentionally and does not return, he/she is considered as disobedient and should pay kaffara of a camel. If he cannot slaughter it, he should fast for eighteen days. Based on caution, camel slaughtering is to be carried out on the day of Eid al-Adha at Mina, though it is not remote to say it is not obligatory to slaughter it in Mina. If he/she returns to 'Arafat before sunset, there would be no need of paying kaffara.
If a person goes out from the land of 'Arafat before sunset forgetfully or ignorantly, it is obligatory to return back upon remembrance before maghrib. In case, he does not come back, he/she has committed disobedience. However there is no kaffara on him. If he comes to know it after the end of the time, he has no duty.