Musannaf Ibn Abi Shayba 16:860

Abu Bakr narrated to us, he said: Abdullah ibn Idris narrated to us, from Abu al-Ashhab, from a man from Muzaynah, that the Messenger of Allah (may Allah bless him and grant him peace) saw a washed garment on Umar. He said: "Is this garment of yours new?" He said: "It is washed, O Messenger of Allah." He said: So the Messenger of Allah (may Allah bless him and grant him peace) said to him: "Wear new (clothes), live praiseworthy, and die a martyr. May Allah grant you coolness of the eyes in this world and the Hereafter."