What is the ruling on zakat for land that was granted and then sold after four years, given the ignorance of the obligation of zakat upon it during that period?

If the intention to trade land was not present at the time of its acquisition, then no zakat is due on it. Zakat becomes obligatory on its price if a year has passed over it and it reaches the nisab. However, if the intention to trade it was present at the time of acquisition, then zakat is obligatory on its value for the past four years, provided it reached the nisab. This applies according to those who do not stipulate that trade goods must be acquired through a contract of exchange. As for those who do stipulate this (such as the Shafi'is), zakat is not obligatory on it if it was a gift. And according to the view that zakat is obligatory, the market value of the land is estimated each year, and 2.5% of the value is paid.