حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ الزُّبَيْرِيُّ حَدَّثَنَا إِسْرَائِيلُ عَنْ سِمَاكٍ عَنْ عِكْرِمَةَ عَنِ ابْنِ عَبَّاسٍ عَنْ عُمَرَ رَضِيَ اللَّهُ عَنْهُ قَالَ كُنْتُ مَعَ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي غَزَاةٍ فَحَلَفْتُ لَا وَأَبِي فَهَتَفَ بِي رَجُلٌ مِنْ خَلْفِي فَقَالَ لَا تَحْلِفُوا بِآبَائِكُمْ فَإِذَا هُوَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ
مسند امام احمد بن حنبل · Hadith 214
It was narrated from Ibn 'Abbas that 'Umar (RA) said: I was with the Prophet (PBUH) on a campaign, and I swore (an oath). No, by my father! A man called out from behind me: "Do not swear by your fathers." And I saw that it was the Prophet (PBUH).
Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020