—without his master’s permission. Should the master authorize him, the transaction stands. The only exception is the mukātib—a slave who has contracted for his freedom—for his buying and selling are valid even without the owner’s leave.

According to Mālik, a blind person may lawfully sell or purchase, whether in a salam contract or otherwise, provided that the commodity reaches him with a clearly defined description, or that someone whom he trusts is present to view it on his behalf. Anyone who alternates between insanity and lucidity may effect a valid sale during his lucid intervals.

A woman’s sale without her husband’s permission is likewise valid. If, however, she shows undue favour in the price, that concession is treated like a gift. Mālik and his companions apply here the one-third rule: while she is healthy, they allow her—without her husband’s consent—to give away up to one third of her wealth; anything beyond a third they do not allow. Their proof is the ḥadīth related by ʿAmr ibn Shuʿayb, from his father, from his grandfather, that the Prophet—may Allah bless him and grant him peace—said: “A woman may not give a gift or dispose of property in any matter except with her husband’s permission.”

Most scholars, however, permit a mature, rational woman to manage her wealth—by gift or otherwise; in their view she is, in that respect, no different from a man.

The sale of a mute person is valid when effected through intelligible signs. Likewise, sales concluded by fathers, guardians, or the ruler’s trustees on behalf of those in their care are valid, provided they serve the ward’s best interest; if excessive loss, favouritism, or injustice is later discovered in any such sale, it is annulled.

When a competent owner sells his own property, mutual bargaining and even favouritism are permissible, just as he may give it away outright.

By contrast, the sale of someone who is forced and pressured is invalid, for he is akin to one coerced into selling; commerce is only sound when both parties consent. As for a person whom debt obliges to sell his goods, or whom dire need and poverty compel to sell, there is no harm in buying from him at the lawful market price.