Haggai 2:20-23 is a prophetic passage where God promises a future of ultimate victory and stability, shaking the nations and establishing His kingdom through the line of David, symbolized by Zerubbabel. God declares that Zerubbabel will be like a signet ring, signifying his divine authority and importance as a placeholder for the coming Messiah. This prophecy provides hope and a vision of God's future kingdom, encouraging the people to remain faithful and obedient, as their actions are part of God's plan to bring about His purposes.