Is it obligatory to perform Hajj on behalf of a son who died at the age of 14?

The heirs must pay for a Hajj on behalf of the deceased child from his estate if he had reached maturity, met the conditions for Hajj's obligation, but did not perform it, and left behind sufficient wealth for the Hajj. This is because Hajj is a debt owed to Allah, and His debt is most worthy of being fulfilled. There is no difference whether a relative or someone else performs the Hajj on his behalf. However, if the child died before reaching maturity, or if Hajj was not obligatory for him due to not possessing sufficient wealth, then Hajj is not obligatory on his behalf.