(36) And the camels and cattle We have appointed for you as among the symbols of Allah; for you therein is good. So mention the name of Allah upon them when lined up [for sacrifice]; and when they are [lifeless] on their sides, then eat from them and feed the needy and the beggar. Thus have We subjected them to you that you may be grateful.
I saw Ibn 'Umar passing by a man who had his camel sit down in order to slaughter it at Mina, so he said: Sacrifice while it is standing and fettered according to the Sunnah of Muhammad (PBUH).
Whoever has slaughtered a sacrifice should not keep anything of its meat after three days. Next year, people said: O Messenger of Allah, will we do as we did last year? He said: Eat, feed, and save from it. Last year, people were going through hard times, so I wanted you to help.