Musnad Abu Ya'la al-Mawsili 140:10

Al-Fadl ibn al-Sabah narrated to us, Abu Ubaydah narrated to us, from Muhtasib, he said: Yazid al-Raqashi narrated to me, from Anas, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "There is no Muslim who witnesses the funeral of a Muslim person except that he has a qirat of reward. If he sits until it is leveled over him, he has two qirats of reward; every qirat is like Uhud."