Thus saith the LORD of hosts; It shall yet come to pass, that there shall come {l} people, and the inhabitants of many cities:

(l) He declares the great zeal that God would give the Gentiles to come to his Church, and to unite with the Jews in his true religion, which would be in the kingdom of Christ.

Wesley's Notes

8:20 People - Multitudes.

Jamieson-Fausset-Brown Bible Commentary

20. (Isa 2:3; Mic 4:2).

Thus saith the Lord of hosts-a preface needed to assure the Jews, now disheartened by the perils surrounding them, and by the humble aspect of the temple. "Unlikely as what follows may seem to you, Jehovah of hosts, boundless in resources, saith it, therefore it shall be so." Just before Christ's coming, a feeling grew up among the heathen of the unsatisfactoriness of their systems of religion and philosophy; this disposed them favorably towards the religion of the Jew, so that proselytes embraced the worship of Jehovah from various parts of Asia; these again were predisposed to embrace Christianity when it was preached to them (Ac 2:9-12, 41). But the full accomplishment of the conversion of the Gentiles foretold here is reserved till "Jerusalem" (Zec 8:22) becomes the center of Christianized Jewry (Ro 11:12, 15).

Matthew Henry's Concise Commentary

8:18-23 When God comes towards us in ways of mercy, we must meet him with joy and thankfulness. Therefore be faithful and honest in all your dealings; and let it be a pleasure to you to be so, though thereby you come short of the gains others get dishonestly; and, as much as in you lies, live peaceably with all men. Let the truths of God rule in your heads, and let the peace of God rule in your hearts. Thus the ancient servants of God drew the notice of heathen neighbours, whose prejudices were softened. A great increase to the church shall be made. Hitherto the Jews had been prone to learn the idolatries of other nations: what more unlikely than that they should teach religion to their conquerors, and to all the principal nations of the earth! Yet this is expressly foretold, and it came to pass. Hitherto the prophecy has been wonderfully fulfilled, and no doubt future events will explain it further. It is good to be with those who have God with them; if we take God for our God, we must take his people for our people, and be willing to take our lot with them. But let not any one think that mere zeal, either for Jews or Gentiles, will stand in the place of personal religion. Let us be living epistles of Christ, known and read of all men, so that others may wish to go with us, and to have their portion with us in the realms of bliss.