A.T. Robertson Commentary John 8:23

"And he said unto them, Ye are from beneath; I am from above: ye are of this world; I am not of this world." — John 8:23 (ASV)

Ye are from beneath (υμεις εκ των κατω). This language, peculiar to John, could take up the idea in Josephus that these rabbis came from Gehenna whence they will go as children of the devil (8:44), but the use of εκ του κοσμου τουτου ("of this world" in origin) as parallel to what we have here seems to prove that the contrast between κατω and ανω here is between the earthly (sensual) and the heavenly as in Jas 3:15-17. See also Col 3:1. This is the only use of κατω in John . These proud rabbis had their origin in this world of darkness (1:9) with all its limitations.

I am from above (εγω εκ των ανω ειμ). The contrast is complete in origin and character, already stated in 3:31, and calculated to intensify their anger.