"had to save up some of your money". Occasionally, the author addresses a proverb to "my son." This is not intended to restrict the words of that proverb to only males. Instead, it is simply a form used to pass on advice as a father does to his son.
your neighbor may come to you to ask for a loan or your neighbor wants to take out a loan from someone else, but you promise to pay the lender back if your neighbor cannot.