To what extent is it permissible for a government entity to request a monthly cash payment from the contractor, and is the project manager sinful for addressing the company about this and delivering the amount, and what is the ruling on adding materials and installations to the invoices (or completion certificates) that were not actually installed, in order to compensate for the amounts paid or to compensate for materials whose item prices are low?

It is not permissible for a government employee to demand money from a company, as it is ill-gotten gain (suḥt) and bribery. Nor is it permissible for the company to pay it, unless it is to ward off injustice. Similarly, it is not permissible for the company to take money from the state in compensation for what employees have taken, for public funds belong to the Muslims. The intermediary in bribery is sinful and accursed, unless it is for delivering a right or lifting an injustice. It is not permissible to add materials that were not installed to the statements to compensate for what the government representative took, as this is deception and consumption of public funds. However, this is permissible if the materials are accounted for at a cost lower than the actual cost, with the knowledge of the government entity, to compensate the contractor, and this is permissible for delivering the right to its rightful owner. A Muslim must beware of injustice, bribery, and lying.