It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "I have been commanded regarding the Day of Sacrifice, an Eid which Allah has appointed for this Ummah." A man said: If I have nothing but my family's milch goat, should I sacrifice it? He (peace and blessings be upon him) said: "No, but clip your nails, shave your pubic hair and trim your moustache; that is the completion of your sacrifice."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13754