`Sayyiduna Ibn Umar (may Allah be pleased with them) narrates that the Messenger of Allah (peace and blessings be upon him) said: Whoever wants to swear an oath should not swear by anyone except Allah. And the Quraysh used to swear by their forefathers, so the Messenger of Allah (peace and blessings be upon him) said: Do not swear by your forefathers.