LEV360 We are forbidden to withhold money that we owe. The prohibition against retaining money refers to someone who accepts money from another person and refuses to return it upon demand. This would include someone who borrows money and does not repay the loan, or an employer who refuses to give an employee his salary. Withholding part of a loan or wages is also included in this prohibition. (Rambam, Hilchos Gzaila v'avaida 1:4). In order not to be guilty of withholding someone's wages, you should always reach an agreement with a worker about his wages before he begins the job. Failure to decide on a price in advance usually leads to arguments later on, with the result of both sides feel cheated. If the employer fails to pay the employee the amount that is customary to pay in his area, the employer is guilty of withholding wages. When a price is decided upon in advance, the employee will usually agree to a lower price than he would afterward, so that besides the spiritual benefits, the employer will also gain financially. If the employer is a Torah scholar, failure to set a price in advance could also lead to a chilul Hashem. The worker might say that Torah scholars are dishonest. (Chofetz Chayim in Sfas Tomim, ch. 5).