Musnad Abu Ya'la al-Mawsili 161:39

Muhammad ibn Ishaq al-Musayyibi narrated to us, Abdullah ibn Nafi’ narrated to us, from ‘Asim, from Suhayl ibn Abi Salih, from his father, from Abu Hurayrah, that the Prophet (peace and blessings of Allah be upon him) said: "Whoever does the deed of the people of Lot, then stone the upper one and the lower one; stone them both together."