Sahih Al Bukhari Hadith Number 953

Narrated Anas bin Malik: Allah’s Messenger (peace be upon him) never proceeded (for the prayer) on the Day of `Id-ul-Fitr unless he had eaten some dates. Anas also narrated: The Prophet (peace be upon him) used to eat odd number of dates.

13  The Two Festivals (Eids)
Hadith number 953
Volume no 2
Chapter: 4 (Eating on the day of Fitr before ethe ‘Eid-al-Fitr)