Haywat bin Sharih bin Safwan حيوة بن شريح بن صفوان التجيبي · Funerals (Kitab Al-Jana'iz)

If anyone attends the funeral and prays over (the dead), he will get the reward of one qirat, and if anyone attends the funeral until the completion (of the burial), he will get the reward of two qirats, the smaller of them being equivalent of Uhud, or one of them being equivalent to Uhud.

One day the Messenger of Allah (ﷺ) went out and prayed over the martyrs of Uhud like his prayer over the dead, and then returned.