Narrated to us by Ali ibn Abdullah, narrated to us by Ibn Wahb, informed me Amr ibn al-Harith, from Bakr ibn Sawadah al-Judhami, from Ziyad ibn Nu'aym al-Hadrami, from Amr ibn Hazm, who said: The Messenger of Allah, peace and blessings be upon him, saw me reclining on a grave, and he said: "Do not harm the occupant of this grave, or do not harm him."
Hadith Referenceمسند احمد / مسند الأنصار رضي الله عنهم / 24009/39