Is a marriage contract valid if the master and his female slave agree that manumission will serve as the dower (mahr)?

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The marriage contract is valid when the master and his female slave agree that her manumission will constitute the dower, and she marries him on that basis. In this case, no dower other than the stipulated manumission is due to her. Abu Yusuf holds this opinion. The primary evidence is that manumission serves as a valid compromise for a dower in the case of the Prophet, peace be upon him, thus it is permissible in the case of his Ummah, similar to dirhams. Furthermore, manumission is a valid consideration in sale contracts; if one says, 'Manumit your slave in exchange for a thousand,' it is permissible, so it is more appropriate for it to be consideration in marriage, as the intent in marriage is not primarily the consideration.