Sahih Bukhari Volume 7, Book 68, Hadith Number 462.

Narrated By ‘Uqba bin ‘Amir : That the Prophet gave him some sheep to distribute among his companions to slaughter as sacrifices (‘Id-al-Adha). A kid was left and he told the Prophet of that whereupon he said to him, “Slaughter it as a sacrifice (on your behalf).”