It is narrated from Hazrat Anas (may Allah be pleased with him) that on the day of Eid al-Fitr, the Prophet (peace and blessings be upon him) would not go towards the Eidgah until he had eaten a few dates one by one.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 12268
Hadith Gradingحکم دارالسلام:حديث صحيح، خ: 953، وهذا إسناد حسن