Musnad Ahmad 30:657

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from al-Zuhri, from Ibn al-Musayyib, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever prays over a funeral, for him is a qirat. And whoever waits for it until it is placed in the lahd (niche in the grave), for him are two qirats." And the two qirats are like two great mountains.