The Cow - 2:196
Complete Hajj and ´Umrah for Allah. If you are prevented, send a sacrifice that is easy for you. Do not shave your heads until the sacrifice has reached its destination, but whoever is sick or has a head ailment should give a ransom in fasting, charity or any other act of worship. Whoever enjoys ´Umrah until the time of Hajj, in a state of safety, should send a sacrifice that is easy for him. Those who are unable to do so should fast for a total of ten days, three days during Hajj and seven days after returning. This is for those whose family does not live near the Holy Mosque. Listen to Allah and know that the punishment of Allah is severe.
The purpose of sacrifice:
The Pilgrimage/22:36
There are benefits for you in the sacrifice of animals as a sign of worshipping Allah. You should mention the name of Allah over them while they are lined up. And when they fall on their sides, eat of them, and feed the beggar and the poor, We have made them available for you so that you may give thanks.
The Pilgrimage/22:37
Neither their flesh nor their blood reaches Allah; only your righteous deeds reach Him. He has made them at your service so that you may remember the greatness of Allah for guiding you to the truth.