What is the legal ruling regarding the dealings of the seller's heirs with a buyer who has not completed payment for land agreed upon 30 years ago, where the buyer offered to pay the remaining amount based on the old price per meter, despite a significant increase in the land's value? And is the contract considered void, entitling the heirs to reclaim the land?

If a father sold land thirty years ago, received two-thirds of the payment, and stipulated that the buyer must pay the remaining one-third within one year, otherwise the land would not be registered in his name, and the buyer delayed payment, then the original principle would be to annul the contract and for the buyer to reclaim what he had paid.

However, after thirty years, the contract cannot be annulled. The remaining amount is not entirely a loan due to its connection with the condition and the long delay. Annuling the contract would harm the buyer, and considering the remaining amount as a debt would harm the seller.

Therefore, the solution is reconciliation and mutual agreement, such as rectifying the contract for two-thirds of the land, excluding the remaining one-third, and the buyer purchasing it at its current price or as agreed upon by both parties.

If the dispute persists, the recourse is to the Sharia courts to examine the text of the contract, hear both parties and witnesses, or resort to the arbitration of scholars and people of religion.