Bequeathing an unstipulated amount for a non-heir

The Fuqaha have stated that if a person bequeaths a portion of his wealth then his heirs will be told to fulfil the Wasiyyat by giving any amount that they (the heirs) wish to give. In other words they (the heirs) will decide and stipulate the amount that the former wife is to receive. The reasoning provided by the jurists is that an ambiguous amount (that is not stipulated by the testator) includes a small amount as well as a large amount. However, such ambiguity does not prevent one from fulfilling the Wasiyyah. In such a scenario, the inheritors become the substitutes of the testator in determining the amount; hence they will be required to provide the amount.