Charles Ellicott Commentary Zechariah 14:9

"And Jehovah shall be King over all the earth: in that day shall Jehovah be one, and his name one." — Zechariah 14:9 (ASV)

All the earth.—In accordance with the context, we can only understand this in the sense of “all the land” (Zechariah 13:8). But though this is undoubtedly the meaning of the prophet, there is no reason why his words may not have a wider application than he himself ever contemplated.

Shall there be one Lord. —Better, Jehovah shall be One: i.e., “God shall be all in all.”

And his name one. — i.e., and He alone shall be worshipped as God.