Hadith on Oaths: Swear by Allah or keep quiet

Abdullah ibn Umar reported: The Messenger of Allah, peace and blessings be upon him, found Umar ibn al-Khattab while he was upon his mount, swearing an oath by his father. The Prophet said, “Surely Allah prohibits you from swearing an oath by your fathers. Whoever swears an oath, let him swear by Allah or remain silent.

Source: Ṣaḥīḥ al-Bukhārī 6270, Ṣaḥīḥ Muslim 3104

Grade: Muttafaqun Alayhi (authenticity agreed upon) according to Al-Bukhari and Muslim

عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَدْرَكَ عُمَرَ بْنَ الْخَطَّابِ وَهُوَ يَسِيرُ فِي رَكْبٍ يَحْلِفُ بِأَبِيهِ فَقَالَ أَلَا إِنَّ اللَّهَ يَنْهَاكُمْ أَنْ تَحْلِفُوا بِآبَائِكُمْ مَنْ كَانَ حَالِفًا فَلْيَحْلِفْ بِاللَّهِ أَوْ لِيَصْمُتْ

6270 صحيح البخاري كتاب الأيمان والنذور باب لا تحلفوا بآبائكم

3104 صحيح مسلم كتاب الأيمان باب النهي عن الحلف بغير الله تعالى