What is the ruling regarding legal punishment (hadd) and dower (mahr) if a mukātab takes a concubine with or without permission?

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If the mukātab has sexual relations with a concubine, whether with or without his master's permission, he incurs no legal punishment (hadd) due to the doubt surrounding his partial ownership. Likewise, no dower is due, as dower, if due, would be due to him, and a person is not obligated to pay something to himself.