Why do banks need security cheque when handling mortgages?

Banks in the United Arab Emirates require security cheque because they are used in cases where the borrower fails to repay the mortgage. In this case, the bank will present the cheque, and if the cheque is cancelled, the bank will initiate legal procedures to take possession of the property to pay the outstanding debts. 

This is not much different from other countries where banks can sign contracts to recover the property owed by customers for mortgage loans.