Is it permissible to eat from an Udhiyah that was purchased from one-third of the deceased's bequest, if the one offering the Udhiyah is the executor of this bequest?

It is not permissible to offer a sacrifice on behalf of the deceased from one-third of his bequeathed wealth if he specified the disbursements of that third and did not mention the sacrifice, as Allah Almighty says: ﴿And whoever alters it after he has heard it – the sin is only upon those who alter it. Indeed, Allah is Hearing and Knowing.﴾ However, if he did not specify particular disbursements for the one-third and said: "It should be spent on acts of righteousness," then it is permissible to offer a sacrifice on his behalf, because sacrificing on behalf of the deceased resembles charity.

Regarding the differing views on the disbursement of the sacrifice for the deceased: - Shafi'is: It is not permissible except by bequest, and all of it must be given in charity to the poor, and the rich are not allowed to eat from it. - Hanafis: If the sacrifice was by bequest from the deceased, all of it must be given in charity. If it was a voluntary offering from a living person, then he is allowed to eat from it. - Hanbalis: There is no difference between it being by bequest or a voluntary offering. It should be treated like the sacrifice of a living person, in terms of eating, gifting, and giving in charity. This is the preponderant view.

Therefore, there is no harm in eating from this sacrifice, gifting from it, and giving charity from it.