What is the ruling when a slave intentionally kills two slaves belonging to one master, considering the master's options?

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If a slave kills two slaves belonging to a single master, the master may execute the killer for the retribution concerning either one of the victims, which forfeits his right to retribution for the other victim. Alternatively, the master may grant pardon in exchange for financial compensation, in which case the combined value of both murdered slaves becomes attached to the killer slave's neck.