Musnad Ahmad 30:3695

'Abd al-Samad narrated to us, Hammad narrated to me, from Suhayl, from his father, from Abu Hurayrah, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever peeps into the house of a people without their permission, and his eye is gouged out, it is wasted (i.e., there is no retaliation or blood money for it)."