The word “weeping” occurs eight times in Isaiah’s prophecy. Four times the weeping is for Moab (15:2, 3, 5; 16:9). Weeping fills Moab to the four corners. Twice it is weeping for Jerusalem in the “valley of vision” prophecy (Isaiah 22:4, 12), where the speaker weeps and, like Jacob mourning for Joseph, refuses comfort when he sees his daughter Jerusalem slain. Hezekiah weeps at the attack from the Assyrians (38:3). Through the first 39 chapters of Isaiah, there is a week of weeping, a sevenfold mourning over Judah and other nations.
Then the theme drops out, as Isaiah assures Judah that the city and temple and nation will be restored. After chapter 38, weeping is mentioned only once more, in Isaiah 65:19, where Yahweh assures His people that He will dry the tears from every eye.