Is a contract of sale valid when made by a sick person granting a concession (muhabah)?

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The contract remains valid according to the majority opinion of scholars. The evidence supporting this is the general permissibility of trade established by the Almighty, saying: "And Allah has permitted trade" (Quran 2:275). Furthermore, since the transaction originates from the proper party concerning the proper subject matter, it is valid, just as it would be for a healthy person. If a person sells their only slave, valued at thirty, for ten during their illness, they have conceded two-thirds of its value. A concession exceeding one-third of the estate during illness is not permitted unless the heirs approve it, in which case the sale becomes binding. If the heirs do not approve and the buyer chooses to rescind the contract, the rescission is permitted because the deal has become partially disadvantageous to him.