Albert Barnes on John 7:52

Art thou also of Galilee? Here is another expression of contempt. To be a Galilean was a term of the highest reproach. They knew well that he was not of Galilee, but they meant to ask whether he also had become a follower of the despised Galilean. Ridicule is not argument, and there is no demonstration in a gibe; but, unhappily, this is the only weapon which the proud and haughty often used in opposing religion.

Ariseth no prophet. That is, there is no prediction that any prophet should come out of Galilee, and especially no prophet that was to attend or precede the Messiah. Comp. Jn 1:46. They assumed, therefore, that Jesus could not be the Christ.

(u) "Out of Galilee" Isa 9:1,2