how did God start a separated nation?
God began the separated nation by calling Abraham out of Syria into Canaan, telling him his descendants would sojourn 430 years and then be brought back to Himself. That period ended when Moses led them out, and prophecy was directed to that nation within a time frame.
Les explains that the main river of Gentile humanity goes on its way, but beginning with the call of Abraham, God is going to bring out a separated nation of people. God told Abraham that he would sojourn 430 years, and then the nation would be brought back to Himself. That 430 years ran from the time Abraham came out of Syria down into Canaan until Moses led them out. Prophecy would be directed to these people within a time frame. The context also notes a later 490-year prophecy from a particular time after the Babylonian captivity, when Nebuchadnezzar came in 606 B.C. and took Daniel and all the Jews captive back to Babylon; the 70-year captivity brought them to about 526 B.C., when Ezra went back by Cyrus's decree to rebuild the temple that Nebuchadnezzar's forces had destroyed.