He was asked—may Allah Most High have mercy on him:

Concerning a man who died leaving considerable wealth and a young child. During his illness, he stipulated in his will that a particular horse of his be sold and its entire price given to someone who would perform the obligatory Hajj on his behalf. The horse was sold for nine hundred dirhams.

The judge intended to hire someone unrelated to the deceased to perform Hajj for this amount. Another man then came and said, “I will perform Hajj for four hundred.” Is this permissible, or must the bequest be carried out as stipulated?

He replied:

Praise be to Allah. Rather, the entire amount he bequeathed must be paid, provided it falls within one-third of his estate. If it exceeds one-third, the heirs are not obliged to pay the excess, unless Hajj was obligatory upon him and the obligatory Hajj cannot be performed [without that amount] (1). And Allah knows best.

He was asked:

Concerning a man who left children and bequeathed one dirham a day to his sister. She was paid this until the funds were exhausted, leaving nothing of the estate except a property yielding six hundred dirhams annually. Should she be given that amount, or one dirham as he bequeathed to her?