Whenever the Prophet ﷺ prayed on the day of Eid or any other day, a spear would be planted in front of him, and he would pray facing it while the people stood behind him.Nafi said, "It is from this practice that the rulers adopted the custom."
حدثنا سويد بن سعيد حدثنا علي بن مسهر عن عبيد الله عن نافع
كان النبي ﷺ إذا صلى يوم عيد أو غيره نصبت الحربة بين يديه فيصلي إليها والناس من خلفه قال نافع فمن ثم اتخذها الأمراء
No references are available.
Bukhari narrated it in "The Book of Prayer," chapter "The Imam's Screen Serves as a Screen for Those Behind Him," hadith no. 494, and Muslim narrated it, etc., hadith no. 501, in "The Book of Prayer," chapter "The Screen of the One Praying and the Recommendation to Pray Facing a Screen," from the hadith of Ubaydullah bin Umar, through this same chain.Harun bin Saeed Ayli narrated to us.