What is the ruling on a son jointly offering a sheep with his father as an udhiyyah? A man wishes to share in a single sheep with his father, each contributing half of its price, so that each owns half the animal. Would such a sacrifice fulfill the Sunnah of sacrifice for both of them?

The udhiyyah is one of the rites and symbols of Islam. Allah Almighty said, “And the camels and cattle We have appointed for you as among the symbols of Allah” (Quran, 22:36). ʿAʾisha, the Mother of the Believers (may Allah be pleased with her) narrated that the Messenger of Allah (peace and blessings be upon him) said, “The son of Adam does not perform any deed on the Day of Sacrifice that is more beloved to Allah than the shedding of blood [of the sacrificial animal]. It will come on the Day of Resurrection with its horns, hair, and hooves. Indeed, the blood reaches Allah before it falls to the ground, so be pleased with your sacrifice”
(recorded by at-Tirmidhi in his Sunan, with this wording, and by al-Bayhaqi in Shuʿab Al-ʾIman).

According to the opinion chosen for fatwa, the sacrifice is a confirmed Sunnah. The Prophet (peace be upon him and his family) performed it, encouraged it, and urged his Companions to observe it. Anas (may Allah be pleased with him) narrated that the
Prophet (peace and blessings be upon him) sacrificed two white, horned rams. He slaughtered them with his own hands, mentioned the name of Allah, glorified Him, and placed his foot on their sides” (recorded by al-Bukhari and Muslim).
 

It is firmly established in Islamic law that the udhiyyah can only be offered from livestock: camels, cattle, goats and sheep. This is agreed upon by the majority of jurists, past and present. See: Al-Tamhid by Imam Ibn ʿAbd al-Barr (23:188) and al-Majmuʿ by Imam al-Nawawi (8:393).

 

Ruling on a son sharing in a sheep with his father

The scenario in question involves two individuals contributing to the price of a single sheep, with each entitled to a share proportionate to his financial contribution. Jurists agree that when a single sheep is offered for sacrifice, it may only be owned and paid for by one person. If more than one individual jointly contributes to its price, the udhiyyah does not fulfill the Sunnah for any of them, since it requires complete ownership by the person offering it. Ibn Rushd al-Hafid noted in Bidayat Al-Mujtahid (2:196), “They [the jurists] unanimously agreed on the prohibition of sharing in a sheep.”

The ruling
Based on the above, the arrangement described in the question does not constitute a valid sacrifice for either the son or his father, even if each pays half of the price and owns half of the animal. A single sheep fulfills the Sunnah for only one person.

And Allah Almighty knows best.