From Sahih Bukhari (Hadith 1712):
Narrated Sahl bin Bakkar:The narration of Anas abridged, saying, "The Prophet (ﷺ) slaughtered seven Budn (camels) while standing, with his own hands. On the day of `Id-ul-Adha he slaughtered (sacrificed) two horned rams, black and white in color
Reference: Bukhari 1712