And it must occur that, as regards anyone that does not come up out of the families of the earth to Jerusalem to bow down to the King, Jehovah of armies, even upon them no pouring rain will occur.

The remnant and the “great crowd” are the very ones who come under the combined attack made by the nations because they remain loyal to the “heavenly Jerusalem.” (Heb. 12:22) The preceding verses (Zech. 14:1-15) describe how God wars against the attacking nations and how he confirms his kingship or sovereignty over our earth.