The answer: Some scholars hold that no zakah is due from him in this case, because it resembles a debt owed by an insolvent person, in that he is unable to dispose of it until he is able to sell it. Once he sells it, we say to him: Pay zakah on it for the year of its sale only.
In reality, this is a concession for the Ummah and accords with the established principles, because this man says: “I am not waiting for its price to rise; rather, I am waiting for someone to say, ‘Sell it to me.’”
The land itself is not inherently zakatable wealth such that we may say that zakah is due on the land itself.
As for money kept in a bank or in a cashbox in order to buy a house to live in, or to use as a bridal dower, it does not increase, yet there is no doubt that zakah is due on it.
The difference between it and unsaleable land is that zakah is due on the cash itself, whereas zakah on trade goods is due according to their value; and during a period of stagnation, its value cannot be realized. It is therefore like a debt owed by an insolvent person.
His statement: “No zakah is due on the wealth of one whose debt reduces it below the minimum taxable threshold,” means that if a person possesses the minimum taxable threshold of gold, silver, grains, crops, or livestock, but has a debt that reduces it below the minimum taxable threshold, then no zakah is due on what he possesses.
For example, a man has one hundred thousand in his possession, but he owes ninety-nine thousand nine hundred. What remains to him is now one hundred, and one hundred is below the minimum taxable threshold; therefore, no zakah is due on it.