Mostly banks borrow from depositors and from the capital markets.
Reserve requirements of that type still do exist in some places (though in some places they've been abolished) but don't really play much of a role in determining how quickly money supply grows any more.
Control over money supply growth is mostly down to interest rates these days.
Similarly, the role reserve requirements used to play in protecting depositors has been replaced by the various "Basel" rules which determine what sources of funding banks can use to fund their loans which depend on the loan book's credit quality, tenor etc.
How did you get the wad of cash in the first place and what is it?
A wad of cash isn’t money. It is nothing more than a receipt for a deposit held at an institution somewhere - that was created as an advance in the past in response to an equivalent loan.
When you deposit a wad of cash in a bank, the bank takes ownership of the deposit in the institution and creates a new deposit in the bank for you. It’s just another loan creating a deposit.
Reserve requirements of that type still do exist in some places (though in some places they've been abolished) but don't really play much of a role in determining how quickly money supply grows any more.
Control over money supply growth is mostly down to interest rates these days.
Similarly, the role reserve requirements used to play in protecting depositors has been replaced by the various "Basel" rules which determine what sources of funding banks can use to fund their loans which depend on the loan book's credit quality, tenor etc.