John Wesley on Haggai 2:23

My servant - A type of him who was God's most beloved servant. As a signet - Which is very highly valued, and carefully kept. So shall the antitypical Zerubbabel, the Messiah, be advanced, loved, and inviolably preserved king, and supreme over his church. He is indeed the signet on God's right - hand. For all power is given to him, and derived from him. In him the great charter of the gospel is signed, and sanctified, and it is in him, that all the promises of God are yea and amen.