Is a bequest (Wasiyyah) valid for a Mukatab (indentured servant)?

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The bequest concerning a Mukatab is valid. The Mukatab is treated as a non-related person in transactions with his master, thus the bequest is permissible. If the master states, 'Forgive some of the Mukatab's installment payments,' they may forgive any amount they wish, whether small or large, from the beginning or the end of the installments.