"You shall not defraud your neighbor"Leviticus 19:13.

It is forbidden to withhold monies owed to another. As opposed to theft or robbery, which involve monies that came into a person's possession in an unlawful manner, this prohibition is addressed to the individual who has not obtained property illegally, but refuses to pay money owed. Examples include an employer who withholds wages and a debtor who refuses to repay a loan.

This prohibition includes flat refusal to pay as well as postponing payment employing deceptive methods.