What was narrated concerning carrying a spear on the day of ‘Eid Sunan Ibn Majah 1305

Arabic hadith text
حَدَّثَنَا سُوَيْدُ بْنُ سَعِيدٍ، حَدَّثَنَا عَلِيُّ بْنُ مُسْهِرٍ، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ كَانَ النَّبِيُّ ـ صلى الله عليه وسلم ـإِذَا صَلَّى يَوْمَ عِيدٍ أَوْ غَيْرَهُ نُصِبَتِ الْحَرْبَةُ بَيْنَ يَدَيْهِ فَيُصَلِّي إِلَيْهَا وَالنَّاسُ مِنْ خَلْفِهِ ‏.‏قَالَ نَافِعٌ فَمِنْ ثَمَّ اتَّخَذَهَا الأُمَرَاءُ
Translation
It wasnarrated that Ibn ‘Umar said

“When the Prophet (ﷺ) prayedonthe day of ‘Eid or on another occasion, a small spear was set up infront of him, and he prayed facing it, and the people were behindhim.”Nafi` said: It is from here that the leaders have taken this practice.