Narrated Ibn Umar: The Messenger of Allah ﷺ 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.
Hadith ReferenceSunan Abi Dawud / Oaths and Vows (Kitab Al-Aiman Wa Al-Nudhur) / Hadith: 3249
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح بخاري (6108) صحيح مسلم (1646)