Isaiah 11:10-12
In that day the Root of Jesse will stand as a banner for the peoples; the nations will rally to Him, and His place of rest will be glorious. In that day the Lord will reach out His hand a second time to reclaim the remnant that is left of His people from Assyria, from Lower Egypt, from Upper Egypt, from Cush, from Elam, from Babylonia, from Hamath and from the islands of the sea. He will raise a banner for the nations and gather the exiles of Israel; He will assemble the scattered people of Judah from the four quarters of the earth.

Jeremiah 51:12
Lift up a banner against the walls of Babylon! Reinforce the guard, station the watchmen, prepare an ambush! The LORD will carry out His purpose, His decree against the people of Babylon.