Bukhari

Narrated `Uqba bin 'Amir Al-Juhani: that the Prophet distributed among his companions some animals for sacrifice (to be slaughtered on `Id-al-Adha). `Uqba's share was a Jadha'a (a six month old goat). `Uqba said, "O Allah's Apostle! I get in my share of Jadha'a (a six month old ram)." The Prophet said, "Slaughter it as a sacrifice."