Hiring is a contract over a benefit in return for a recompense. The first condition for the validity of the contract of hiring is the legal competence of the two contractors, such that each of them has reached the age of maturity. Another condition for its validity is the consent of the two contractors. Moreover the wage should be known, due to the saying of the Prophet (pbuh): “If anyone of you hires a worker, He has to inform Him of his wage”, narrated by Ad-Daraqutni from Ibn Mas’oud. Also due to the Hadith narrated by Ahmed from Aby Sa’id that the Prophet (pbuh) forbade hiring a worker without explaining to Him his wage. However, if the wage was not defined, the hiring would be contracted and valid (legal). In case of dispute over the wage, reference is made to the equivalent wage. So if the wage was not defined at the time of the contract and if the employer and the employee then dispute over the wage, then the equivalent wage is adopted. The equivalent wage is adopted by analogy with the disputed marriage money (Dowry), which is decided by referring it to the equivalent dowry if it was not mentioned before, or if a dispute over the named amount occurred. This is due to what Ahmed narrated that ‘Abdullah ibn Mas’oud (ra) judged in the case of a man who passed away before sleeping with a woman, whom He had married without naming the dowry. He said: “She deserves the dowry of her equivalent woman, and she has to do the Iddah (waiting period for the next marriage) and she deserves to inherit from him.” Ma’qal ibn Sinan Al-Ashja’i said: “The Prophet (pbuh) has judged to Barwa’a, daughter of Washiq one of our people, as you judged.” The meaning of saying that she deserved the dowry of her equivalent women means a dowry identical to the dowry of equivalent women. So Shar’a obliged giving the equivalent dowry to the one whose dowry was not named. The same judgement is given in the case where a dispute occurs over the named dowry. Since the dowry is a recompense in the marriage contract, then recompense of any contract can be measured with it. Thus it is judged by the equivalent recompense in case the recompense was not mentioned in a contract, or in the case of dispute over the named recompense. Therefore, it is judged by the equivalent wage in the hiring, and by the equivalent price in the trading (selling) in the case where the price was not named in the contract, or there was a dispute over the named price. Therefore the equivalent wage resolves the case in a dispute between the employee and the employer over the named wage, and in the case where the wage was not mentioned. So, if the wage was mentioned in the contract then the wage would be the named one. But if it was not mentioned or if a dispute occurred over the named wage, then the equivalent wage would be judged as the wage. Thus, the wage is of two different kinds: A named wage and the equivalent wage. The condition for considering the named wage is its acceptance by the two contractors. So if the two contractors accepted a certain wage, then this wage will be the named one, and the employer would not be obliged to pay more than it, nor would the employee be obliged to take less than it, rather it is the binding legal wage. The equivalent wage is the wage for equivalent work, or of the equivalent worker if the contract of the hiring had been concluded over the benefit of the work. The equivalent wage would be the wage of the equivalent worker only if the hiring contract was stated over the benefit of the hired person.

Those who are considered to estimate the wage are the experts in defining wages, not the State, nor the traditions of the population. Rather they are the experts on the wage for the relevant type of work, or the wage for the type of workers for whom the wage is intended to be estimated.

The basis upon which the experts estimate the wage is the benefit, whether it was for the work or the worker. Because the hiring contract is based on the benefit, it becomes the basis upon which the wage estimation is built. Thus the wage is not estimated by the production of the worker or by the lowest standard of living among his community. There is no consideration to the production of the worker nor to the high standard of living in its estimation, rather its estimation is related to the benefit. The experts estimate the wage of the worker according to the value of this benefit in the society in which they live. When the experts estimate the wage for the work and the wage of the worker, they consider the value of the benefit in the community, so they estimate it by the value of the benefit produced by the worker, or benefit of the work. If a dispute occurred over the estimation of the benefit in the community, then it should not be estimated by evidence and proof. Rather it is enough to take the opinion of the experts, because the question is to estimate the value of the benefit and not to establish an evidence about its amount.

Thus, the basis upon which the estimation of the wage is built is the benefit according to the estimation of the experts. But when the experts estimate the equivalent wage, they have to consider not only the wage of the work or the worker alone, because the wage varies with the work, worker, time and place. Rather they are obliged to look to the person who is identical to the worker doing the same work, which is to look to the work, the worker, and at the same time, they have to look at the time and place of work, because the wage differs with the work, worker, the time and the place.

The contracting parties, that is the employer and employee, originally select the experts who estimate the wage or the equivalent wage. If they did not select the experts or differed over their selection, then the court or the State is the competent authority to appoint these experts.