Isaiah 49: 20-21.
20 The children which thou shalt have, after thou hast lost the other, shall say again in thine ears, The place is too strait for me: give place to me that I may dwell.
21 Then shalt thou say in thine heart, Who hath begotten me these, seeing I have lost my children, and am desolate, a captive, and removing to and fro? and who hath brought up these? Behold, I was left alone; these, where had they been?
In the day when all Israelites from the four corners of the earth shall return to Israel, there will be so many that they will be asking, “Where have all these come from?”The land will seem too small to contain them. God will touch the hearts of the Gentile nations to help the regathering of Israel, and then they will worship Messiah, Who will reign in Israel.
We need to keep in mind that the regathering spoken of here will happen after the Rapture, the seven years of the Great Tribulation, and the Battle of Armageddon. The Jews will have suffered terribly during this time, more than at any other time in their history, even including the Holocaust. Those who survive and return to Israel will have lost so much–families, possessions, even the opportunity to have children–that they will be amazed at the numbers returning to Israel from all over the world.