Musannaf Ibn Abi Shayba 27:359

Abu Mu’awiyah narrated to us, from Khalaf ibn Hawshab, from Abu al-Safar, who said: A *burd* (garment) was seen on Ali, which he used to wear frequently. It was said to him, "You wear this *burd* very often." He said, "My intimate friend, my chosen one, my close companion, and my special one, Umar, clothed me with it. Indeed, Umar gave sincere advice to Allah, so Allah gave him sincere advice." Then he wept.