What is the ruling on selling a plot of land in exchange for a debt amount, if the price of the land exceeds the indebted amount and the debt was not paid within the agreed-upon period?

If the sales contract is made contingent upon the condition of non-payment, it is impermissible due to the contingency of the sale, and stipulating a loan within a forbidden sales contract makes the sale null and void. However, if the land is mortgaged for the loan, the mortgage cannot be taken possession of unless the debt maturity date has arrived and the borrower has abstained from payment or is absent. The matter must be presented to the Sharia courts for the sale of the mortgage.