Musnad Abu Ya'la al-Mawsili 112:27

We were with the Messenger of Allah (peace and blessings of Allah be upon him), and Umar ibn al-Khattab was with him. The Messenger of Allah was upon a bed made of palm-fiber strips, with nothing between the side of the Messenger of Allah (peace and blessings of Allah be upon him) and the strips. He was the softest of people in skin. He turned slightly, and the strips had left a mark on the skin of his side or his flank. Umar wept, so the Messenger of Allah (peace and blessings of Allah be upon him) said, "What makes you weep?" He said, "By Allah, O Messenger of Allah, I do not weep because I do not know that you are more noble to Allah than Caesar and Chosroes. They revel in what they revel in of the world, while you are the Messenger of Allah in the state that I see." He said, "O Umar, are you not pleased that the Hereafter is for us and the world is for them?" He said, "Yes." He said, "It is indeed so."