Allah says in the Qur'an:
ﭽ ﭾ ﭿ ﮀ ﮁ ﮂ ﮃ ﮄ ﮅ ﮆ ﮇ ﮈ ﮉ ﮊﮋ ﮌ ﮍ ﮎ ﮏ ﮐﮑ ﮒ ﮓ ﮔ ﭼ
Meaning: “And for all religion We have appointed a rite [of sacrifice] that they may mention the name of Allah over what He has provided for them of [sacrificial] animals. For your god is one God, so to Him submit. And, [O Muhammad], give good tidings to the humble [before their Lord]” (Q22:V34).
Below are some rules pertaining to the sacrificial animal in Islam:
That the animal has to be one of the cattle approved by the Shari'ah; as Allaah says: ﭽ ﭑ ﭒﭓ ﭔ ﭕ ﭖ ﭗ ﭘ ﭙﭚ ﭼ
Meaning: “Eight are the pairs: of the sheep two (male and female), and of the goats two (male and female).” (Q6:V143). The next verse also says:
ﭽ ﭬ ﭭ ﭮ ﭯ ﭰ ﭱﭲ ﭼ
Meaning: “And of the camels two (male and female), and of oxen two (male and female). (Q6:V13)
A sheep or goat is used as a single offering and is sufficient for one household;
Abu AyUb al Ansaree (may Allaah be pleased with him) said: “At the time of the Messenger of Allah (peace and blessings of Allah be upon him), a man would sacrifice a sheep on behalf of himself and the members of his household, and they would eat from it and give some to others.” (Reported by Ibn Maajah and al-Tirmidhi)
A camel or cow can be shared by seven people, because of the report narrated by Jaabir (may Allah be pleased with him) who said: “We sacrificed at al-Hudaybiyah with the Prophet (peace and blessings of Allah be upon him), a camel for seven and a cow for seven.” Narrated Muslim.
The animal has reached the required age: The Prophet (peace and blessings of Allah be upon him) said: “Do not sacrifice anything but an adult animal, unless it is difficult for you, in which case you may slaughter a six-month old lamb (jadh'ah).” Narrated by Muslim
The adult age is:
One year for a goat or sheep
Two years for a cow
Five years for a camel
The animal is free of an obvious defect: The Prophet (peace and blessings of Allah be upon him) said: “There are four that will not do for sacrifice: a one-eyed animal whose defect is obvious, a sick animal whose sickness is obvious, a lame animal whose limp is obvious and an emaciated animal that has no marrow in its bones.” (Saheeh al-Jaami', no. 886).
There are milder defects that do not disqualify an animal, but it is makrooh to sacrifice such animals, such as an animal with a horn or ear missing, or an animal with slits in its ears, etc.
The animal is in full possession of the one who is offering the sacrifice; i.e. it is not stolen or taken by force, is of joint possession or held in pledge.
The animal cannot be sold or given away once selected or bought for sacrifice, unless exchanging for something better. If an animal gives birth, its offspring should be sacrificed along with it.
Rules related to the meat and other parts of sacrificial animal
Eating on the day of Eid from the meat of sacrifice: Buraydah (may Allaah be pleased with him) said: “The Messenger of Allaah (peace and blessings of Allaah be upon him) did not go out on the day of (Eid) al-Fitr until he had eaten, and he did not eat on the day of (Eid) al-Adha until he came back, then he would eat from his sacrifice.” (narrated Ahmad)
It is recommended to divide the meat into three: one third to be eaten, one third to be given as gifts and one third to be given in charity. This was the opinion of Ibn Mas'ood and Ibn ‘Umar (may Allah be pleased with them).
No part of the slaughter can be sold or given as payment: The Prophet (peace and blessings of Allah be upon him) said: “Whoever sells the skin of his udhiyah, there is no udhiyah for him (i.e., it is not counted as udhiyah).” (Saheeh al-Jaami', 6118).
The butcher should not be given anything of it by way of payment, because ‘Ali (may Allah be pleased with him) said: “The Messenger of Allah (peace and blessings of Allah be upon him) commanded me to take care of the sacrifice and to give its meat, skin and raiment (covering used for protection) in charity, and not to give anything of it to the butcher as a compensation. He said, ‘We will give him something from what we have.'” (Agreed upon).