مُسْنَدُ أَحْمَدَ
Musnad Ahmad 214
Musnad `Umar b. al-Khattab (ra)
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.
It was narrated from Ibn 'Abbas that 'Umar رضي الله عنه said: I was with the Prophet (ﷺ) 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 (ﷺ).
Musnad Ahmad, 214Sahih lighairihi and its isnad is da'eef al-Bukhari (6647) M