The rich rule over the poor, and the borrower is slave to the lender.
This verse is one of the plainest warnings against taking on debt in the Bible. Before that, let’s look at the relationship between rich and poor. It says the rich rule over the poor. (It doesn’t say the rich should rule over the poor, just that they do.) And this is clear to see. Imagine you had a million dollars to spend. How many people could you rule over? You can say what should be done, and it gets done. You have the money to make people fall in line. You can act like a king in that position. The relationship between the rich at the poor is like the relationship between a king and his subjects. The king speaks and the subjects act.
Then it also says that the relationship between borrower and lender is like a slave-master relationship. If you owe someone money, they call the shots. If you took out a huge student loan, but then had a desire to change you career trajectory in a less lucrative but more fulfilling direction, you may not have that choice. The lender will be paid, and so they can force actions that you didn’t want to take. It is not wise to voluntarily put yourself in the position of a slave underneath a moneylender.