Jesus answered is literally “and he said to them.” In both sentences of this verse the pronouns you and I are emphatic.

You belong to this world here below, but I come from above is literally “You are from below, I am from above” (Revised Standard Version). In the last part of this verse “from below” is explained as meaning from this world; it stands in contrast to the world above, where God is. Good News Translation makes “from below” explicit by rendering you belong to this world. The same contrast is found in 3.31, where the words from above are contrasted with from the earth.

In some languages it may not make sense to say “You are from here below,” for that would be saying that Jesus’ listeners had come from a place where they already were, or from a place even lower than that! Likewise, it is almost meaningless to say “you come from this world.” What is evidently intended by Jesus is to say that, in contradistinction to himself, the people to whom he was speaking were associated with this world, while he himself had his true connection with heaven. The contrast may be expressed in some languages as “You belong to this world below, while I belong to the world above” or “… to heaven above.” The contrast may also be expressed in some languages as “you belong to this world below, while I come from above” or “… I come from heaven.” The final statement in verse 23 may then be rendered “You belong to this world, but I do not belong to this world.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .