Subcontracting and making gains

(Part No. 14; Page No. 377)  A: If you have a contract to do some work in a building for one hundred thousand riyals and then you bring workers who do it for twenty thousand Riyals, then there is no harm in taking the rest of money i.e. The eighty thousand Riyals in the question. May Allah grant us success. May peace and blessings of Allah be upon our Prophet Muhammad, his family and Companions!