Hazrat Umar (may Allah be pleased with him) narrated that the Prophet Muhammad (peace and blessings be upon him) said to me that Allah Almighty has forbidden you from swearing by your forefathers. Hazrat Umar (may Allah be pleased with him) narrated, "By Allah! After I heard this prohibition from the Prophet (peace and blessings be upon him), I never swore an oath, neither by anything other than Allah from myself nor by quoting it from someone else's tongue."