Sayyiduna Ibn Umar (may Allah be pleased with him) narrates from the Noble Prophet (peace and blessings be upon him) that he (peace be upon him) would plant a spear (as a sutrah) and pray. And Ashajj states that he (peace be upon him) would plant a spear (or lance) in front of him. He would not mention anything more than this.
It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that a spear would be fixed for the Prophet (peace and blessings of Allah be upon him), and he (peace be upon him) would use it as a sutrah and perform prayer on the day of Eid.