Sayyiduna Abdullah bin Umar (may Allah be pleased with them) narrates that the Prophet Muhammad (peace and blessings be upon him) heard Sayyiduna Umar (may Allah be pleased with him) saying: "By my father! By my father!" The Prophet (peace and blessings be upon him) said: "Allah forbids you from swearing by your forefathers." Sayyiduna Umar narrates: "By Allah! After that, I never swore by my father, neither while speaking myself nor while quoting anyone else."