Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) said that a man came to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Allah has made the day of sacrifice a day of Eid for this Ummah." The man said: What if I slaughter the milk-giving animal of my children and family? He (peace and blessings be upon him) said: "Do not slaughter the milk-giving animal; but clip your nails, shave your moustache and remove your pubic hair. In this way you will receive from Allah the reward of a complete sacrifice."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19028