´Ibn Abi Najib narrated from his father who said:` "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."
Hadith Referenceسنن ترمذي / كتاب الصيام عن رسول الله صلى الله عليه وسلم / 751
Hadith Gradingالألبانی:صحيح الإسناد | زبیر علی زئی:(751) إسناده ضعيف, ابن أبى نجيع مدلس و عنعن و فى السند رجل سقط عن سند الترمذي (انظر مسند الحميدي بتحقيقي :682)