And indeed We know that they (polytheists and pagans) say: “It is only a human being who teaches the Prophet (Muhammad SAW).” The tongue of the man they refer to is foreign, while this (the Quran) is a clear Arabic language.Meaning:-
Polytheists: The worship of or belief in more than one god, belief in many gods.
Pagans: is a person who worships many gods or who worships nature and the Earth.