Charles Ellicott Commentary Zechariah 14:17

"And it shall be, that whoso of [all] the families of the earth goeth not up unto Jerusalem to worship the King, Jehovah of hosts, upon them there shall be no rain." — Zechariah 14:17 (ASV)

No rain. —Though the worship of the Lord is to become universal, apostasy is not regarded as impossible. The punishment for such deflection is spoken of in such figurative language as suits the symbolic description of the nations’ conversion.