Sahih Bukhari

Narrated Ibn `Umar:I heard `Umar saying, ""Allah's Messenger (ﷺ) said to me, 'Allah forbids you to swear by your fathers."" `Umar said, ""By Allah! Since I heard that from the Prophet (ﷺ) , I have not taken such an oath, neither intentionally, nor by reporting the oath of someone else