What is the ruling on opening a restaurant inside a shisha cafe?

We have previously clarified that the use of shisha is forbidden due to its harms. If it is established that it is forbidden, then it is not permissible for a Muslim to open a restaurant in a café that serves shisha, as this involves witnessing a prohibited act. Nor is it permissible for him to be present in a place where a prohibited act is occurring, except with the intention of denouncing it, due to the Almighty's saying: "And when you see those who engage in [blasphemous] discourse about Our verses, then turn away from them until they enter into another conversation." However, if the restaurant is in an independent part of the café such that one does not see the prohibited act, and opening it does not directly aid in that sin, then there is no harm in that.