(Imām Bukhārī narrates): Muhammad bin Bashshar narrated to us, he said: Abdul Wahhab narrated to us, he said: Ubaidullah narrated to us from Nafi' from Ibn Umar, may Allāh be pleased with them both, he relates that
on Eid al-Fitr and Eid al-Adha, a spear would be planted in front of the Prophet ﷺ, then he would pray.
Reference: Sahih Al Bukhari 972