Musnad Ahmad 1132:2

Yahya ibn Ishaq narrated to us, Ibn Lahi'ah narrated to us, from Bakr ibn Sawadah, from Ziyad ibn Nu'aym, from 'Amr ibn Hazm, who said: The Messenger of Allah (peace and blessings of Allah be upon him) saw me on a grave and said: "Get down, do not harm the occupant of this grave." Ziyad ibn Nu'aym said in another place that Ibn Hazm—either 'Amr or 'Umarah—said: The Messenger of Allah (peace and blessings of Allah be upon him) saw me on a grave...