Musnad Ahmad 30:3206

Muhammad ibn Ja‘far and ‘Affan narrated to us, they said: Shu‘bah narrated to us, from Sulayman, from Dhakwan, from Abu Hurayrah, from the Prophet, peace and blessings of Allah be upon him, who said: "O Allah, I am only a human being, so whichever Muslim I have whipped—Ibn Ja‘far said: or insulted, or cursed—then make it for him a purification, a reward, and a means of drawing near by which he may draw near to You on the Day of Resurrection."