in relation to wealth means handling it properly, for some terms are interpreted in each context according to what is appropriate.

Second: he must be sane; the opposite is insanity. The evidence for this is that Allah stipulated the presence of sound judgment, and sound judgment can never coexist with insanity.

Third: he must be free; the opposite of a free person is a slave. A slave’s guarantee is not valid, because a slave may not dispose of property except with his master’s permission.

Fourth: he must be financially sound. A financially sound person is one who manages his wealth properly. The jurists, may Allah have mercy on them, said: he must not spend wealth on something prohibited or on something that brings no benefit.

Is this restriction acceptable?

The answer is no. For if we accepted it, all smokers would be deemed financially irresponsible and lacking sound judgment, and we would place them all under financial interdiction.

Rather, we say that a financially sound person is one who manages his wealth properly in buying, selling, leasing out, renting, mortgaging, taking pledges, and similar transactions.

As for not spending it on something prohibited or the like, there is no doubt that one who spends it on what is prohibited is foolish; however, this is not the kind of foolishness that prevents a person from disposing of property. Otherwise, we would be obliged to place under financial interdiction everyone who deals in something prohibited.

Therefore, a guarantee issued by a minor is invalid. If a minor wished to act as a guarantor, it would not be valid, even for something insignificant. For example, if some boys were buying and selling chickens, and one sold to another, and the seller said, “I will not accept this unless you bring a guarantor,” whereupon he replied, “This is my companion,” and his companion was likewise a boy, then this would not be valid, because he is not legally competent to dispose of property, being a minor.