What does Isaiah 27:13 mean?
Isaiah looks forward to the day, in the end times, when the Lord will bring home all who belong to Him. The sound of a trumpet was often used as a signal. Here, it means it is time to come in, to return, to come home. Isaiah's trumpet for the people of Israel to be gathered fits with Paul's description of the trumpet blast that will be heard at Christ's coming: "For the Lord himself will descend from heaven with a cry of command, with the voice of an archangel, and with the sound of the trumpet of God. And the dead in Christ will rise first" (1 Thessalonians 4:16).Isaiah also reports on the future return of those scattered into Assyria and Egypt. In a literal sense, the captives of prior conquests would one day be allowed to come home (Ezra 2:1). In a secondary, further sense, during the end times, Israel will once again thrive in her own lands (Micah 4:7–8; Daniel 2:44).
This was meant to encourage those facing exile far away from Jerusalem in foreign lands. Modern Christians can enjoy a similar reassurance. There will be a resurrection (1 Corinthians 15:52). The Lord will come for you. You will "return" (Hebrews 11:16) when the time is right, even if it is in the last days.