The willingness of a lender to give a mortgage to a mortgagor. A mortgage commitment will give a time period the mortgage will be given and an indication of the interest rate to be charged on the mortgage. The mortgage will actually be granted at a closing. For example, John obtains a mortgage commitment from a bank to give him a $100,000 mortgage to buy a home for $150,000. The closing will be in six weeks and the bank gives a lock-in clause of 8% on the mortgage.