Sunan Abi Dawud — The Rites of Hajj (Kitab Al-Manasik Wa'l-Hajj) — Hadith No: 1768
Translation
Ziyad bin Jubair said :I was present with Ibn `Umar at Minah. He passed a man who was sacrificing his camel while it was sitting. He said make it stand and tie its leg ; thus follow the practice (sunnah) of Muhammad (SWAS)