Spending the night at 'Arafat due to an excuse
Is it permissible for a pilgrim to proceed to Arafat on the eighth day of Dhul-Hijah instead of going to Mina because of the crowding that occurs while climbing up to 'Arafa?
The eighth day of Dhul-Hijah is the day of Tarwiah [the eighth rest]. It is called this because traditionally the pilgrims would rest themselves, their animals' and voluntary sacrifices, and give them water on their way to 'Arafat, in preparation for that great day and the other ceremonies of 'Eid, the Day of sacrifice, and the three days following Eid [ayam al-tashreeq].
It is a sunna and not an obligation for the pilgrim to proceed to Mina in mid-morning and pray the Noon, Mid-afternoon, Sunset and Night Prayers, shortening the four raka’ prayers to two raka’s but without combining them. [It is likewise a sunna] to spend the night in Mina to pray Fajr and then set out to 'Arafat at mid-morning.
If a pilgrim who is elderly, ailing or incapable of going to Mina for any reason, did anything in contrast to this and went to 'Arafat on the eighth day to avoid the crowds, there is nothing on him and his pilgrimage is valid. What matters is that he has left a recommended act for an excuse, and perhaps he will be rewarded for the thing he would have done if not for the excuse. Expiation is due in case of omitting an obligation not a sunna. It would be better for him to spend the day of Tarwiah at Mina and then spend the eve of the 9th of Dhul-Hijja at 'Arafat due to the crowds.
Allah the Almighty and Majestic knows best