Musnad Ahmad 30:235

Sufyan narrated to us—I asked him—from Sumayy, from Abu Salih, from Abu Hurairah, from the Prophet (peace and blessings of Allah be upon him): "Whoever prays over a funeral, for him is a qirat. And whoever follows it until its affair is finished, for him are two qirats; the smaller of them, or one of them, is like Uhud."