Is Zakat obligatory on a sum of four thousand dollars resulting from the sale of gold on which Zakat was previously paid?

Whoever has paid Zakat on gold and then sells it is not required to pay Zakat again upon selling it. Rather, Zakat becomes due again only after a full year has passed since the previous Zakat payment, provided that the wealth reaches the nisab (threshold) either by itself or when combined with other forms of wealth.