Why did muhammad refer to jews and christians as "people of the book"

Regardless of the breadth of the definition attached to the term law, there is an essential truth to the fact that at the core of the nation's expansive legal system lays a body of enforceable written rules meant to maintain order, define the outer limits of our interactions with one another and with our governments, and delineate legal rights and responsibilities. these rules derive from several sources, which collectively are called primary sources of law. there are also secondary sources of law, which are not laws in the technical sense for this assignment, identify and discuss the four types of primary sources of law. in your response, be sure to define each one. discuss what types of laws are derived from each source. identify the source of authority for each one. lastly, provide an example of a law from each source.