It Is Disliked To Swear By One's Forefathers
حَدَّثَنَا أَحْمَدُ بْنُ حَنْبَلٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، حَدَّثَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنْ سَالِمٍ، عَنْ أَبِيهِ، عَنْ عُمَرَ، - رضى الله عنه - قَالَ سَمِعَنِي رَسُولُ اللَّهِ صلى الله عليه وسلم نَحْوَ مَعْنَاهُ إِلَى " بِآبَائِكُمْ " . زَادَ قَالَ عُمَرُ فَوَاللَّهِ مَا حَلَفْتُ بِهَذَا ذَاكِرًا وَلاَ آثِرًا .
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."