Commentaries:
When does this happen? This takes place in the early stages of the Millennium. Finally, Israel comes to the conclusion that He is their God. Of course, as events transpire, they will probably be getting pretty good hints, but at least in the way God sets matters up here, they do not really understand until they see this prophecy being fulfilled before their eyes: Kings of other nations are acting as the "tutors" of their children. They are being served by the leaders of these other nations. There is no other reason for this happening except that God has caused it to occur. They will begin to see God working, and that is when their understanding dawns!
Richard T. Ritenbaugh
The Two Witnesses (Part One)