ʿUmar ؓ said: I was marching with a group of people on a campaign with the Messenger of Allah ﷺ, and I swore, saying: No, by my father. A man behind me called out: “Do not swear by your fathers.ʿ I turned around and saw it was the Messenger of Allah ﷺ.
عَبَّاسٍقَالَ قَالَ عُمَرُ كُنْتُ فِي رَكْبٍ أَسِيرُ فِي غَزَاةٍ مَعَ رَسُولِ اللهِ ﷺ فَحَلَفْتُ فَقُلْتُ لَا وَأَبِي فَهَتَفَ بِي رَجُلٌ مِنْ خَلْفِي لَا تَحْلِفُوابِآبَائِكُمْ فَالْتَفَتُّ فَإِذَا هُوَ رَسُولُ اللهِ ﷺ