What is the ruling on conditional manumission contingent upon death (Tadbir Muqayyad)?

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Conditional manumission contingent upon death is divided into two types: specific and general condition. The specific type includes conditions tied to the master's present circumstances, such as saying, 'If I die from this illness,' or 'If I die during this journey,' or 'If I die in this year.' If the slave fulfills the condition specified (i.e., the master dies under that specific circumstance), the slave is manumitted; otherwise, he is not manumitted. Imam Ahmad confirmed that if one says to his slave, 'You are a Mudabbir today,' the slave becomes Mudabbir for that day, and if the master dies that day, the slave becomes free.