Language:
كتاب الأيمان والنذور
83  
Oaths and Vows
(4)
Chapter: "Do not swear by your fathers"
(4)
باب لاَ تَحْلِفُوا بِآبَائِكُمْ
Sahih al-Bukhari 6646

Narrated Ibn `Umar:

Allah's Messenger (ﷺ) met `Umar bin Al-Khattab while the latter was going with a group of camel-riders, and he was swearing by his father. The Prophet (ﷺ) said, "Lo! Allah forbids you to swear by your fathers, so whoever has to take an oath, he should swear by Allah or keep quiet."

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَدْرَكَ عُمَرَ بْنَ الْخَطَّابِ وَهْوَ يَسِيرُ فِي رَكْبٍ يَحْلِفُ بِأَبِيهِ فَقَالَ ‏ "‏ أَلاَ إِنَّ اللَّهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ، مَنْ كَانَ حَالِفًا فَلْيَحْلِفْ بِاللَّهِ، أَوْ لِيَصْمُتْ ‏"‏‏.‏
Reference : Sahih al-Bukhari 6646
In-book reference : Book 83, Hadith 25
USC-MSA web (English) reference : Vol. 8, Book 78, Hadith 641
  (deprecated numbering scheme)