Musannaf Ibn Abi Shayba 6:818

Waki’ narrated to us, from Isma’il bin Abi Khalid, from Salim al-Barrad, from Ibn ‘Umar; and from Hisham, from Sa’id al-Maqburi, from Abu Hurayrah; and from his father, from ‘Asim, from Zirr, from ‘Abdullah, they said: Whoever prays over a funeral, for him is a qirat. And whoever attends it until its completion is finished, for him are two qirats. The qirat is like Uhud.