Zechariah 8:19 – “Thus saith the LORD of hosts; The fast of the fourth month, and the fast of the fifth, and the fast of the seventh, and the fast of the tenth, shall be to the house of Judah joy and gladness, and cheerful feasts; therefore love the truth and peace.”
The Fast of Tammuz begins a three-week season of mourning and repentance. The first fast reminded Jews of the day when the wall of Jerusalem was breached by the Babylonians in 587 B.C. (and later by the Romans in 70 A.D.) The Fast of Ab three weeks later designates the complete destruction of the Temple and Israel carried off into captivity. The focus of this season is on the idolatry that brought God’s judgment upon them, and a search to rid ourselves of any idolatry within ourselves.
The medieval Jewish commentator Maimonides said that all these fasts would cease in the times of the Messiah. So Zechariah’s prophesy points to God’s final victory, which as believers we celebrate from our position as “seated with him in the heavenlies.”