Sahih Bukhari
Representation, Authorization, Business by Proxy
Volume: 003 / Book Number: 038 / Hadith Number: 497
Narrated 'Uqba bin Amir:
that the Prophet had given him sheep to distribute among his companions and a male kid was left (after the distribution). When he informed the Prophet of it, he said (to him), "Offer it as a sacrifice on your behalf."