'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."
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا أَبُو مُعَاوِيَةَ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، - رضى الله عنها - قَالَتْ كَانَ قُرَيْشٌ وَمَنْ دَانَ دِينَهَا يَقِفُونَ بِالْمُزْدَلِفَةِ وَكَانُوا يُسَمَّوْنَ الْحُمْسَ وَكَانَ سَائِرُ الْعَرَبِ يَقِفُونَ بِعَرَفَةَ فَلَمَّا جَاءَ الإِسْلاَمُ أَمَرَ اللَّهُ عَزَّ وَجَلَّ نَبِيَّهُ صلى الله عليه وسلم أَنْ يَأْتِيَ عَرَفَاتٍ فَيَقِفَ بِهَا ثُمَّ يُفِيضَ مِنْهَا فَذَلِكَ قَوْلُهُ عَزَّ وَجَلَّ { ثُمَّ أَفِيضُوا مِنْ حَيْثُ أَفَاضَ النَّاسُ}
Muslim
The Book of Pilgrimage • Hadith 163