(253) باب التَّكْبِيرِ فِي الْعِيدَيْنِ
Narrated Aisha, Ummul Mu'minin:
The Messenger of Allah (ﷺ) would say the takbir (Allah is most great) seven times in the first rak'ah and five times in the second rak'ah on the day of the breaking of the fast and on the day of sacrifice (on the occasion of both the 'Id prayers, the two festivals).
Reference: Sunan Abi Dawud 1149
In-book reference: Book 2, Hadith 760
English translation: Book 3, Hadith 1145