CHAPTER: It Is Disliked To Swear By One’s Forefathers.
Narrated Abu Hurairah: The Prophet صلی اللہ علیہ وسلم said: Do not swear by your fathers, or by your mothers, or by rivals to Allah; and swear by Allah only, and swear by Allah only when you are speaking the truth.
Narrated Ibn Umar: The Messenger of Allah صلی اللہ علیہ وسلم found Umar al-Khattab in a caravan while he was swearing by his father. So he said: Allah forbids you to swear by forefathers. If anyone swears, he must swear by Allah or keep silence.
The tradition mentioned above has also been transmitted by Ibn Umar through a different chain of narrators to the same effect up to the words by your fathers . This version adds: Umar said: I swear by Allah, I never swore by it personally or reporting it from others.
Saeed ibn Ubaydah said: Ibn Umar heard a man swearing: No, I swear by the Kabah. Ibn Umar said to him: I heard the Messenger of Allah صلی اللہ علیہ وسلم say: He who swears by anyone but Allah is polytheist.
Referring to the story of a bedouin, Talhah bin Ubaid Allah reported the Prophet صلی اللہ علیہ وسلم as saying: He became successful, by his father, if he speaks the truth, he will enter paradise, by his father, if he speaks truth.