The Quraish people and those who embraced their religion, used to stay at Muzdalifa and used to call themselves Al-Hums, while the rest of the Arabs used to stay at `Arafat. When Islam came, Allah ordered His Prophet to go to `Arafat and stay at it, and then pass on from there, and that is what is meant by the Statement of Allah:--"Then depart from the place whence all the people depart......" (2.199)
Sahih al-Bukhari Book 65, Hadith 45
← Previous Hadith `Ukaz, Mijanna and Dhul-Majaz were markets during the Pre-islamic Period. They (i.e. Muslims) considered it a sin to trade there during the Hajj time (i.e. season), so this Verse was revealed:-- "There is no harm for you if you seek of the Bounty of your Lord during the Hajj season." (2.198)

Sahih al-Bukhari Book 65, Hadith 44 Next Hadith → A man who wants to perform the Hajj (from Mecca) can perform the Tawaf around the Ka`ba as long as he is not in the state of Ihram till he assumes the Ihram for Hajj. Then, if he rides and proceeds to `Arafat, he should take a Hadi (i.e. animal for sacrifice), either a camel or a cow or a sheep, whatever he can afford; but if he cannot afford it, he should fast for three days during the Hajj before the day of `Arafat, but if the third day of his fasting happens to be the day of `Arafat (i.e. 9th of Dhul-Hijja) then it is no sin for him (to fast on it). Then he should proceed to `Arafat and stay there from the time of the `Asr prayer till darkness falls. Then the pilgrims should proceed from `Arafat, and when they have departed from it, they reach Jam' (i.e. Al-Muzdalifa) where they ask Allah to help them to be righteous and dutiful to Him, and there they remember Allah greatly or say Takbir (i.e. Allah is Greater) and Tahlil (i.e. None has the right to be worshipped but Allah) repeatedly before dawn breaks. Then, after offering the morning (Fajr) prayer you should pass on (to Mina) for the people used to do so and Allah said:-- "Then depart from the place whence all the people depart. And ask for Allah's Forgiveness. Truly! Allah is Oft-Forgiving, Most Merciful." (2.199) Then you should go on doing so till you throw pebbles over the Jamra.

Sahih al-Bukhari Book 65, Hadith 46