What does "Tawqeefiyyah acts of worship" mean?

The meaning of the scholars' statement: "Acts of worship are tawqifiyyah (divinely ordained and unalterable)" is that it is impermissible to worship Allah through an act of worship unless its legitimacy is established by evidence from the Qur'an and Sunnah. Allah has perfected the religion, and whatever He has not legislated is not part of it. Therefore, every act of worship must be commanded by Islamic law. The basic principle concerning acts of worship is prohibition and prevention unless there is religious evidence for their permissibility.