Charles Ellicott Commentary Haggai 2:23

"In that day, saith Jehovah of hosts, will I take thee, O Zerubbabel, my servant, the son of Shealtiel, saith Jehovah, and will make thee as a signet; for I have chosen thee, saith Jehovah of hosts." — Haggai 2:23 (ASV)

Signet: On the figure of the signet-ring applied to one on whom confidence and affection are bestowed, see Song of Solomon 8:6; Jeremiah 22:24.