Musnad Ahmad 5:299

Aswad ibn Amir narrated to us, Shu'bah narrated to us, from Abu al-Tayyah, [who said]: I heard Abdullah ibn Abi al-Hudhayl al-'Anazi narrating from a man from Banu Asad, who said: Ali came out to us, and he mentioned the like of the hadith of Suwayd ibn Sa'id: "I was with Umar while he was covered in his garment."