In addition to other responses, and if the lender is a bank, and given a fractional reserve banking system - it's possible that the lender doesn't actually pay

In addition to other responses, and if the lender is a bank, and given a fractional reserve banking system - it's possible that the lender doesn't actually pay the amount loaned out of their own assets. It just counts against the amount which, multiplied by the reserve fraction, must be backed by a reserve. So assuming a fraction of 1/10, it is somewhat as though they had loaned out a tenth of the money the lender actually gets.