When a bank loans 10,000 dollars, the amount is credited to a checking account. It does not have to come from somewhere else. What use would a loan be if you kept it in your checking?
Don't take my word for it, take it from the Bank of England's Quarterly Bulletin [0] "Banks create create additional broad money whenever they create a loan... it runs contrary to the view sometimes put forward that banks can only lend out deposits that they already have. In fact, Loans create deposits, not the other way around."