Yahya related to me from Malik from Hisham ibn Urwa that hisfather said, "Someone who does not stand at Arafa on the night ofMuzdalifabefore the dawn breaks has missed the hajj, andsome one who stands at Arafa on the night of Muzdalifa before the dawnbreaks has caught the hajj.Malik said, about a slave freedduring the wuquf at Arafa, "His standing does not fulfil for him thehajj of Islam, except if he was not in ihram and then he went intoihram after he was freed and he stood at Arafa that same night beforethe dawn broke in which case that is enough for him. If, however, hedid not go into ihram until after the dawn had broken, he is in thesame position as someone who misses the hajj by not catching thestanding at Arafa before the breaking of the dawn on the night ofMuzdalifa, and he will have to do the hajj of Islam later."
USC-MSA web (English) reference: Book 20, Hadith 179
Arabic reference: Book 20, Hadith 879