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."

Hazrat Ibn Umar (may Allah be pleased with them both) came to Hazrat Umar bin Khattab (may Allah be pleased with him), who was with a few horsemen. At that time, Hazrat Umar (may Allah be pleased with him) was swearing by his father. Upon this, the Messenger of Allah (peace and blessings be upon him) called out to him and said, "Be aware! Surely Allah the Pure forbids you from swearing by your forefathers. So if anyone must swear, let him swear by Allah, otherwise he should remain silent."