Is it permissible to perform Hajj on behalf of a deceased brother, and can the expenses of Hajj be divided and taken from his heirs, or must it be solely from the wealth of the volunteer?

If a Muslim dies and was unable to perform the Hajj pilgrimage due to not meeting the conditions of capability (istita'ah), then Hajj is not obligatory on their behalf. However, if Hajj became obligatory upon them and they did not perform it, scholars have differed regarding the ruling of performing Hajj on their behalf. According to Abu Hanifa and Malik, Hajj is not to be performed on their behalf unless it is by way of a bequest and voluntary contribution. Whereas, Al-Shafi'i and Ahmad are of the view that it is obligatory to perform Hajj on their behalf from their estate, whether they made a will or not, and this is the more preponderant opinion. If they do not have an estate, then their heirs are not obligated to perform Hajj on their behalf, but it is commendable for them to do so. The obligation is lifted from them if an heir, a hired person, or a stranger performs Hajj on their behalf.