What does John 7:50 mean?

Unfair stereotypes are just that—unfair—even in a context which heavily reinforces them. The term "Pharisee" has a terrible reputation in modern minds. The word immediately evokes ideas like "judgmental," "hypocritical," "arrogant," and "rigid." Certainly, those were legitimate criticisms of many Pharisees, as mentioned by Jesus Himself. And yet, in Jesus' era, the Pharisees were also known for being extremely moral, highly educated, and eminently respectable men. Nicodemus is an example of how that combination of intellect and conviction is meant to operate. Unfortunately, it earns him insults and ridicule from his peers when it comes to Jesus.

The Pharisees are caught in a fit of rage over the failure of their officials to arrest Jesus. Their primary argument against Jesus is pure arrogance: "He does not agree with us, so He must be wrong." Nicodemus has visited Jesus to investigate His claims reasonably and respectfully (John 3:1–2). Here, Nicodemus merely suggests the Pharisees give Jesus due process: to fully hear Him out before dismissing Him as wrong.

In response, his peers will not only continue to display arrogance, but they will even insult Nicodemus with an ethnic remark. That is followed by an ironically ignorant challenge about Scripture (John 7:52).