Isaiah 4-

1 And in that day seven women shall take hold of one man, saying, “We will eat our own bread, and wear our own apparel: only let us be called by thy name, to take away our reproach.”
There will be so few men left after the war that women will be willing to work full time supporting themselves if a man will only marry them.

Women, by their created biology, have times of weakness and vulnerability due to pregnancy and nursing. This is one reason God instituted marriage; to provide for women when they are most in need and free them to care for the next generation. With no men, this set up is threatened.

2 In that day shall the branch of the LORD be beautiful and glorious, and the fruit of the earth shall be excellent and comely for them that are escaped of Israel.

The Branch is Jesus. Those that survive to His time will be blessed to see it.

3 And it shall come to pass, that he that is left in Zion, and he that remaineth in Jerusalem, shall be called holy, even every one that is written among the living in Jerusalem:

4 When the Lord shall have washed away the filth of the daughters of Zion, and shall have purged the blood of Jerusalem from the midst thereof by the spirit of judgment, and by the spirit of burning.

All Israel/Judah was purged, pruned and purified to make them ready for Christ.

5 And the LORD will create upon every dwelling place of mount Zion, and upon her assemblies, a cloud and smoke by day, and the shining of a flaming fire by night: for upon all the glory shall be a defense.

Symbolism= the fire and cloud of Moses time that led and protected Israel. This protection will be on everyone who serves God.

6 And there shall be a tabernacle for a shadow in the daytime from the heat, and for a place of refuge, and for a covert from storm and from rain.

God provides protection.