حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَدْرَكَ عُمَرَ بْنَ الْخَطَّابِ - رضى الله عنه - وَهُوَ يَسِيرُ فِي رَكْبٍ وَهُوَ يَحْلِفُ بِأَبِيهِ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ اللَّهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ فَمَنْ كَانَ حَالِفًا فَلْيَحْلِفْ بِاللَّهِ أَوْ لِيَصْمُتْ " .
Yahya related to me from Malik from Nafi from Abdullah ibn Umarthat one time the Messenger of Allah, may Allah bless him and granthim peace, was speaking to Umar ibn al-Khattab while he was travellingwith a troop and Umar swore by his father and he (the Messenger) said,"Allah forbids you to swear by your fathers. If anyone swears, let himswear by Allah or keep silent." Translation Not Available
Book Ref: Muwatta Imam Malik Book 22 Hadith 1027
Web Ref: Muwatta Imam Malik Book 22 Hadith 14