Dictionary.net

Or living pledge, contracts. When a man borrows a sum of money (suppose two hundred dollars) of another, and grants him an estate, as of twenty dollars per annum, to hold till the rents and profits shall repay the sum so borrowed.

This is an estate conditioned to be void as soon as such sum is raised. And in this case the land or pledge is said to be living; it subsists, and survives the debt, and immediately on the discharge, of that, results back to the borrower. 2 Bl. Com. 157. See Antichresis; Mortgage.