As regards the issue of udhiyah and its conditions, we would like to stress that udhiyah is one of the great rituals of Islam, in which we remember the Unity of Allah, His Blessings upon us and the obedience of our father Ibrahim to his Lord, and in this act of udhiyah there is much goodness and blessing. So the Muslim must pay attention to its great importance. The following is a brief look at this important ritual.
In this regard, we would like to cite the following:

Udhiyah refers to the animal (camel, cattle or sheep) offered as a sacrifice, and it as an act of worship dedicated solely to gain Pleasure of Allah. Udhiyah takes place in the country in which the person offering the sacrifice lives, during the period from after the `Eid Prayer on the Day of nahr or `Eid Al-Adha until the last of the Days of tashreeq (the 13th day of Dhul-Hijjah), with the intention of offering sacrifice.  Allah says: (Therefore turn in prayer to your Lord and sacrifice (to Him only).) (Al-Kawthar 108: 2).
He also says: (Say (O Muhammad): ‘Verily, my prayer, my sacrifice, my living and my dying are for Allah, the Lord of the `Alameen (mankind, jinn and all that exists).) (Al-An`am 6:162).
(And for every nation We have appointed religious ceremonies, that they may mention the Name of Allah over the beast of cattle that He has given them for food. And your God is One God, so you must submit to Him Alone (in Islam)…) (Al-Hajj 22:34)

Udhiyah is a confirmed Sunnah (Sunnah Muakkadah) according to the majority of scholars (some scholars say that it is wajib or obligatory; this will be discussed in more detail below).

The basic principle is that it is required at the appointed time from one who is alive on behalf of himself and the members of his household, and he may include in the reward whoever he wishes, living or dead.

Conditions of Udhiyah:

1. The animal should have reached the required age, which is six months for a lamb, one year for a goat, two years for a cow and five years for a camel.

2. It should be free of any faults, because the Prophet (peace and blessing 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.” (Sahih Al-Jami`, no. 886). There are milder defects that do not disqualify an animal, but it is makruh to sacrifice such animals, such as an animal with a horn or ear missing, or an animal with slits in its ears, etc.

Udhiyah is an act of worship to Allah, and Allah is Good and accepts only that which is good. “Whoever honors the rites of Allah, this has to do with the piety of the heart” (al-Hajj 22:32)

3. It is forbidden to sell it. If an animal has been selected for sacrifice, it is not permissible to sell it or give it away, except in exchange for one that is better. If an animal gives birth, its offspring should be sacrificed along with it. It is also permissible to ride it if necessary. The evidence for this is the report narrated by al-Bukhari and Muslim from Abu Hurayrah, may Allah be pleased with him, who said that the Messenger of Allah (peace and blessings be upon him) saw a man leading his camel and told him, “Ride it.” He said, “It is for sacrifice.” He said, “Ride it” a second or third time. (Sahih al-Bukhari)

4. It should be sacrificed at the specified time, which is from after the prayer and khutbah of `Eid – not from when the time for the prayer and khutbah starts – until before sunset on the last day of tashreeq, which is the 13th day of Dhul-Hijjah. The Prophet (peace and blessing be upon him) is reported to have said: “Whoever sacrifices before the prayer, let him repeat it.” (Reported by Al-Bukhari and Muslim). `Ali, may Allah be pleased with him, said: “The days of nahr or sacrifice are the day of al-Adha and the three days following it.” This is also the opinion of Al-Hasan Al-Basri, `Ata’ Ibn Abu Rabah, Al-Auza`i, Ash-Shafi`i and Ibn Al-Mundhir, may Allah have mercy on them all.

What should be done with the sacrifice?

1. It is mustahabb or preferable for one who has made a sacrifice not to eat anything on that day before he eats from it, if this is possible, because of the Hadith, “Let every man eat from his sacrifice.” (Sahih Al-Jami`, 5349). This eating should be after the `Eid Prayer and khutbah. This is the opinion of the scholars, including `Ali, Ibn `Abbas, Malik, Ash-Shafi`i and others. The evidence for this is the Hadith of Buraidah, may Allah be pleased with him: “The Prophet (peace and blessing be upon him) would not go out on the Day of fitr until he had eaten, and he would not eat on the day of adha until he had slaughtered (his sacrifice).” (Al-Albani said: Its Isnad (Chain of Transmission) is Sahih. Al-Mishkat, 1/452).

2. It is better for a person to slaughter the sacrifice himself, but if he does not, it is mustahabb for him to be present when it is slaughtered.

3. It is mustahabb to divide the meat into three: one third for consumption, one third to be given as gifts and one third to be given in charity. This was the opinion of Ibn Mas`ud and Ibn `Umar, may Allah be pleased with them. The scholars agreed that it is not permissible to sell anything from its meat, fat or skin. In a Sahih Hadith, the Prophet (peace and blessing be upon him) is reported to have said: “Whoever sells the skin of his udhiyah, there is no udhiyahfor him (i.e., it is not counted as udhiyah).” (Sahih Al-Jami`, 6118). The butcher should not be given anything of it by way of reward or payment, because `Ali, may Allah be pleased with him, said: “The Messenger of Allah (peace and blessings 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 by Al-Bukhari and Muslim). It was said that it is permissible to give the butcher something as a gift, and that it is permissible to give some of it to a Kafir (i.e., non-Muslim) if he is poor or a relative or a neighbor, or in order to open his heart to Islam.