Sahih al-Bukhari 6108
صحيح البخاري#6108Sahihحَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا لَيْثٌ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما أَنَّهُ أَدْرَكَ عُمَرَ بْنَ الْخَطَّابِ فِي رَكْبٍ وَهْوَ يَحْلِفُ بِأَبِيهِ، فَنَادَاهُمْ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَلاَ إِنَّ اللَّهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ، فَمَنْ كَانَ حَالِفًا فَلْيَحْلِفْ بِاللَّهِ، وَإِلاَّ فَلْيَصْمُتْ ".
Narrated Ibn `Umar:that he found `Umar bin Al-Khattab in a group of people and he was swearing by his father. So Allah's Messenger (ﷺ) called them, saying, "Verily! Allah forbids you to swear by your fathers. If one has to take an oath, he should swear by Allah or otherwise keep quiet
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 78:135