Sheikh Hânî al-Jubayr, judge at the Jeddah Supreme Court
The moment you sold the land, it ceased to be your property and became the property of the buyer who purchased it through the estate agency. This is because a contract of sale is a binding contract and neither party can back out of without the other party’s agreement.
It is immaterial that the buyer was unknown to you at the time of sale. This is because you sold the property through an intermediary who described the sale to you. Your lack of personal acquaintance with the buyer has no affect on the validity of the sale. Neither does the fact that you have yet to receive payment. The validity of a sales contract is not contingent upon these factors.
If you really want to keep the property, then I suggest that you try and negotiate some agreement with the buyer so that he will back down on his right, even if you must pay him something in compensation. Otherwise, you should take the purchase price from the buyer and transfer title to him.
However, if the sale had been made by the agent with an undervalued sale price, then you will have a right to refuse to sell, because the agent had defrauded you.
And Allah knows best.
Source: Islam Today