Sahih Muslim
The Book of Sacrifices (Kitab Al-Adahi)
Book Number: 022 / Hadith Number: 4838
Uqba b. 'Amir reported that Allah's Messenger (may peace be upon him) gave the gifts of goats to be distributed amongst his Companions. They sacrificed them, but a lamb of one year of age was left. (Someone) made a mention of that to the Messenger of Allah (may peace be upon him), whereupon he said: You sacrifice it.