The Messenger of Allah ﷺ heard me swearing an oath by my father and said: “Allah forbids you to swear by your fathers.” ‘Umar said: By Allah, I never swore by my father after that, whether saying it myself or narrating what someone else had said. (Using translation from Aḥmad 241)   

سَمِعَ النَّبِيَّ ﷺ عُمَرَ وَهُوَ يَقُولُ وَأَبِي وَأَبِي فَقَالَ «إِنَّ اللهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ» قَالَ عُمَرُ فَوَاللهِ مَا حَلَفْتُ بِهَا بَعْدُ ذَاكِرًا وَلَا آثِرًا  

"Allah forbids you to swear by your forefathers." 'Umar said: "By Allah, I never swore by them again, whether saying it for myself or reporting of others." (Using translation from Nasāʾī 3767)  

أَنَّ النَّبِيَّ ﷺ قَالَ «أَلَا إِنَّ اللهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ فَوَاللهِ مَا حَلَفْتُ بِهَا بَعْدُ ذَاكِرًا وَلَا آثِرًا»  

"Allah forbids you to swear by your forefathers." 'Umar said: "By Allah, I never swore by them again, whether saying it for myself or reporting of others." (Using translation from Nasāʾī 3767)  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ «إِنَّ اللهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ» قَالَ عُمَرُ فَوَاللهِ مَا حَلَفْتُ بِهَا بَعْدُ ذَاكِرًا وَلَا آثِرًا