How can a person who owns property but has no liquid assets beyond what is necessary to support his family pay his Zakat, especially since selling the property would incur a financial loss?

If the property is for residence, there is no Zakat due on it, because Zakat is due on growing wealth or wealth intended for growth, not on personal possessions, as the Prophet, peace and blessings be upon him, said: "There is no Sadaqah (Zakat) on a Muslim's slave or horse."

However, if the property is merchandise for trade and you incurred losses from its sale due to a decrease in value, and you do not have liquidity for Zakat, then it is permissible to postpone the Zakat until it is sold. The property should be valued each year separately, and Zakat for the past years should be paid.

If the property is for rent, there is no Zakat on the property itself, but rather on the rental income if it reaches the Nisab and a hawl (a lunar year) has passed over it. The Nisab is equivalent to 85 grams of gold, and 2.5% of it is to be given as Zakat.