The correct phrase is actually, "if you build it, he will come" - he, not they.

this was what the voice told Ray Kinsella, played by Kevin Costner, about building a baseball diamond in the movie Field of Dreams. After he built the field, Shoeless Joe Jackson, the "he" that was referred to by the voice to Kinsella, and other dead baseball players came to play ball.

It seems Egyptian President Abdel El-Sisi wants things to work the other way around.

El-Sisi said that if the Jews decide to return to Egypt and rebuild the Jewish community there, the government would build them the synagogues and other community buildings.

El-Sisi actually spoke positively of the rich Jewish past in Egypt and expressed his hope that the Jews would return.
source: JPost

I don't know how far back El-Sisi referred to when he referred to the rich past of the Jewish people in Egypt. Was he only referring to the Jewish community that was there prior to the formation of the Stat of Israel? Was he referring also to the Jews in Egypt a few thousand years ago that were a hard working people who were instrumental in building the infrastructure of Egypt and did not demand exorbitant wages?

I am pretty sure that the Jewish community will not be returning, at least not in large numbers, to Egypt... I can't know for sure - I mean, now there is even a nice sized Jewish community in Berlin and also communities in other cities in Germany...

Well, if the Jews move back to Egypt, the government will build them their synagogues... I guess that is somewhat tempting..