Musannaf Ibn Abi Shayba 35:209

Ibn Fudayl narrated to us, from al-A’mash, from Abu Qays, from ‘Abd al-Rahman ibn Tharwan, from Huzayl, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "If a man were to look into the house of a people through a hole, and he was struck with a date pit that put out his eye, it would be void (i.e., there is no liability for it)." And he mentioned that Abu Hanifah said: "He is liable."