"Ibn Umar was asked about fasting (the Day of) Arafah (at Arafat). He said: 'I performed Hajj with the Prophet, and he did not fast it, and with Abu Bakr, and he did not fast it, and with Umar, and he did not fast it, and with Uthman, and he did not fast it. I do no fast it, nor order it nor forbid it." (Using translation from Tirmidhī 751)
حَجَجْتُ مَعَ النَّبِيِّ ﷺ فَلَمْ يَصُمْهُ وَحَجَجْتُ مَعَ أَبِي بَكْرٍ فَلَمْ يَصُمْهُ وَحَجَجْتُ مَعَ عُمَرَ فَلَمْ يَصُمْهُ وَحَجَجْتُ مَعَ عُثْمَانَ فَلَمْ يَصُمْهُ وَأَنَا لَا أَصُومُهُ وَلَا آمُرُ بِهِ وَلَا أَنْهَى عَنْهُ وَقَالَ سُفْيَانُ مَرَّةً عَمَّنْ سَأَلَ ابْنَ عُمَرَ