Muhammad ibn Ahmad ibn Yahya, from Ya'qub ibn Yazid, from Ziyad ibn Marwan Al-Qandi, from Yunus ibn Zabyan, from Abu Abdullah عليه السلام, who said: Imam عليه السلام said: "The Messenger of Allah سبحانه وتعالى, peace and blessings be upon him and his family, prohibited praying over a grave, sitting on it, or building over it."