Sahih al-Bukhari 3836
Sahih al-Bukhari · Book 63: Merits of the Helpers in Madinah (Ansaar) · The days of Pre-Islamic Period of Ignorance
Narrated Ibn `Umar:
حَدَّثَنَا قُتَيْبَةُ ، حَدَّثَنَا إِسْمَاعِيلُ بْنُ جَعْفَرٍ ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " أَلاَ مَنْ كَانَ حَالِفًا فَلاَ يَحْلِفْ إِلاَّ بِاللَّهِ ". فَكَانَتْ قُرَيْشٌ تَحْلِفُ بِآبَائِهَا، فَقَالَ " لاَ تَحْلِفُوا بِآبَائِكُمْ " .
The Prophet (ﷺ) said, "If anybody has to take an oath, he should swear only by Allah." The people of Quraish used to swear by their fathers, but the Prophet (ﷺ) said, "Do not swear by your fathers. "