Arabic (Original)
أَخْبَرَنَا أَبُو عَبْدِ اللهِ الْحَافِظُ أَخْبَرَنِي أَبُو بَكْرِ بْنُ عَبْدِ اللهِ أنبأ الْحَسَنُ بْنُ سُفْيَانَ ثنا مُحَمَّدُ بْنُ عَبْدِ اللهِ بْنِ نُمَيْرٍ ثنا أَبِي ثنا عُبَيْدُ اللهِ عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ أَنَّ رَسُولَ اللهِ ﷺ كَانَ إِذَا خَرَجَ يَوْمَ الْعِيدِ أَمَرَ بِالْحَرْبَةِ فَتُوضَعُ بَيْنَ يَدَيْهِ فَيُصَلِّي إِلَيْهَا وَالنَّاسُ وَرَاءَهُ وَكَانَ يَفْعَلُ ذَلِكَ فِي السَّفَرِ فَمِنْ ثَمَّ اتَّخَذَهَا الْأُمَرَاءُ
English Translation
Abu Abdullah al-Hafiz informed us... from Nafi', from Ibn Umar, that the Messenger of Allah (peace be upon him), when he went out on the day of Eid, would order the spear to be placed in front of him and would pray facing it, with the people behind him. He also used to do this during travel, and from that practice the rulers adopted it.