As for the material means of production and various tools which a man makes use of in the operation of production. If these means are to be the property of an individual other than the labourer, then the legitimate owner of these tools will be paid for their use. 
It is mentioned in Shara‟i by Muhaqqiq-al- Hilli “if a man gives for example an animal and another man his water skin to a water carrier with the understanding of sharing in the earnings there for, no partnership will take place, so in such a case whatever is earned will belong to the water carrier and compensation for the use of the animal and the water skin will be due from him” 
According to Sadr, here lies the major ideological difference between capitalism and Islam. The former regards the owner of the means of production as the sole owner of the produced commodities, while as Islam considers only the labourer to have the legitimate claim to the commodities produced. In capitalism tools get a share of the product because their use, like human labour represents expenditure of work in the production process. In Islam tools only assist and aid man to facilitate the process of production. Thus they must be compensated for rent only and not in profit sharing. In this way the role of man according to Sadr in the capitalist view is that of means which serve production and not the end which production serves. As for the status of man in Islamic view, it is that of an end and not that of means. Accordingly, only the labourer has the legitimate claim to the products of his effort. Therefore, it is unthinkable in Islamic economics, states Sadr, for someone to employ others and provide them with rent and tools so that he alone owns the production of their labour. 
It is mentioned by Allamah-al-Hilli in his book ash Shar‟i‟, “if a person appoints another person as his wakil (Agent) to cut wood from the forest on his behalf, the Wikalah will be null and void. The appointer will not become the owner of the wood cut by his agent, the reason being that, the labour work produces no special right for a person, until he himself performs the labour.” He also links together Wikalah (agency) and Ijarah (hire work) and then states, “When Wikalah is in productive in regard to those works then Ijarah is also like it. So just as the appointer does not acquire the ownership of cutting of wood or hunting a prey or reclaiming a waste-land by the labour of his agent so naturally the hirer of the labour does not acquire the yield of the labour of the workman hired by him.” 
As for the production of secondary commodities, Islam gives the owner of primacy commodities the right to establish his claim to final products. The legitimacy of his ownership does not cease because, someone aids him in transforming his commodity in different forms. For instance, if a person spins yarns or weaves a fabric out a quantity of wool which a shepherd owns. He will have no claim to the possession of wool but the whole of the woolen fabric will be considered as the property of the shepherd. Sadr calls it the „Phenomenon of the constancy of ownership.‟
The whole theory of post production can be thus summarized as: the material for the production of which a man carries out his labour, when it does not happen to be already an owned property of another man, then the wealth which he produces will be wholly and solely his own property and all the other forces participating in its production will be regarded as his servants and will meet their remuneration at his hand and not partners in the manufactured company. But when the material is to be 
an already owned property of some particular individual, then in such a case, it will continue to remain, according to the „phenomenon of the constancy of ownership‟ the private property of that man whatever changes it may undergo.