Can an invalid Mukatabah contract be dissolved by either the master or the slave?
General Chapter
Al-Mughni
Book of Mukātaba (Contractual Manumission)
Primary text
Either the master or the Mukatab has the right to dissolve and revoke an invalid Mukatabah contract, regardless of whether a condition for manumission was attached. This is the position of Al-Shafi'i's companions because the invalid contract does not enforce its ruling. The condition for manumission here is dependent on the exchange, which is the primary objective; nullifying the exchange nullifies the dependent condition, unlike a pure condition.
Supporting text
The master did not consent to this condition except upon receiving the stipulated consideration; thus, if the consideration is not delivered, he has the right to invalidate it, unlike in a valid Mukatabah where the consideration has been delivered, making the contract binding.