From Sahih Muslim (Hadith 2954):
A'isha (Allah be pleased with her) reported that the Quraish (of the pre-Islamic days) and those who followed their religions practices stayed at Muzdalifa, and they named themselves as Hums, whereas all other Arabs stayed at 'Arafa. With the advent of Islam, Allah, the Exalted and Glorious, commanded His Apostle (ﷺ) to come to 'Arafat and stay there, and then hurry from there, and this is the significance of the words of Allah:" Then hasten on from where the people hasten on
Reference: Muslim 2954