It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that for the Prophet (peace and blessings be upon him) a spear would be planted on the two Eids, and the Prophet (peace and blessings be upon him) would use it as a sutrah and perform the prayer.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5840
Hadith Gradingحکم دارالسلام:حديث صيح، العمري- وإن كان ضعيفا- قد توبع.