I vowed to slaughter a ewe. When the condition of the vow was met, I found that one of my friends had also vowed to slaughter a ewe. So we agreed to slaughter a large cow together instead of two ewes. A friend of ours was blessed with a baby girl, and he wants to make ‘Aqeeqah); so, he wants to take a share in the cow. Is this permissible?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

That your colleague and you slaughter a cow together instead of the two vowed ewes is a controversial issue among the people of knowledge. They hold different opinions as to whether or not this clears the vow-maker of his liability. According to Shaafi‘i scholars, there is nothing wrong in this form of sharing. Imaam An-Nawawi said:

"If one vowed to slaughter a ewe but then replaced it with a camel, then know that this is permissible and that there is no difference of opinion about this among the scholars. As regards whether it is obligatory to offer all of it in fulfillment of the vow, there are two well-known opinions concerning this point. The more correct of them is that one-seventh of the slaughtered animal is considered obligatory and that the rest is voluntary. Therefore, if he replaces the ewe with one seventh of a camel, then it is permissible that others share in the camel with him."

He also said:

"A camel fulfills the obligation for seven people. This also applies to a cow, whether all of them intend it to be a sacrificial animal or some of them intend it as such while the others just want the meat, whether they all belong to the same household or not, and whether the sacrificial animal is offered voluntarily or vowed." [Al-Majmoo‘]

According to the Hanafi and the Maaliki scholars, the vow-maker should fulfill his vow exactly as he intended it to be. It does not clear him of his liability if he replaces the vowed object with something else unless he is unable to fulfill the original vow.

In Bada’i‘ As-Sana’i‘, Al-Kasani, a Hanafi scholar said, "It is obligatory to fulfill the original vow as long as this is possible. If this is not possible, then it should be fulfilled through any alternative because the alternative substitutes the original just like dust (used to obtain ritual purification) in case there is no water."

Ad-Dusooqi commented on the Ad-Dardeer's explanation of the statement of Khaleel, "One is obliged to slaughter a camel if he vowed to do so. If he is unable to do that, then he may slaughter a cow. He (Khaleel) mentioned the camel in particular, although other animals, like a sheep, should be slaughtered if one vows to do so."

Thus, the issue is controversial among the people of knowledge. It is safer in terms of piety and preservation of one's religion that each of them fulfills the vow that he had specified, which is slaughtering a ewe, in order for them to stay away from the difference in the scholars' opinions.

As for the ‘Aqeeqah, it is not valid to share in the cow.

Allaah Knows best.