Many peoples and strong nations shall come to seek the LORD of hosts in Jerusalem and to entreat the favor of the LORD.
God's jealousy here is not reproof for the Church's unfaithfulness, but His burning concern for her protection. The verb means affection and care, not suspicion; He burned with wrath against all enemies of His people while regarding His Church with singular love. His resolve was to defend the godly against the whole world if necessary.
AI summary
Commenting on Zechariah 8:1-23
These verses contain two precious promises, for the further encouragement of those pious Jews that were hearty in building the temple. I. That a happy period should be put to their fasts, and there should be no more occasion for them, but they should be converted into thanksgiving days, Zac 8:19. This is a direct answer to the enquiry concerning their fasts, Zac 7:3.
Commenting on Zechariah 8:18-23
many . . . strong nations . . . in Jerusalem--In contrast to the few and weak Jews now building the temple and city, then such shall be their influence that many and strong nations shall come to worship Jehovah their God in Jerusalem (Isa 60:3; Isa 66:23).