Lanvega, Could we have a better clarification of your question?
If your asking could some one OTHER then the buyer have a life time lease on a property that has a mortgage on?
My guess is that would be an investment property. The BUYER would need approx or a minimum of 30% down payment on that property to purchase.
and quite possibly, only 70% of that lease income would count to the payment qualification for the buyer.
There may be other qualifications for the buyer.
that property may be considered commercial property, so qualifications or income requirements are different. History of property management, or investment, commercial property ownership history too.
The un answered question may be, Why?
Best of luck to you