This verse continues Isaiah’s condemnation of the people of Judah, whom he compared to dancing girls (see note on Isaiah 3:16). He declared that God would take away all evidence of Judah’s pride, symbolized by the fine clothes and jewelry worn by these dancing girls.
These items included their headbands and their necklaces with charms in the shape of crescent moons. These “crescent necklaces” may have signified Judah’s lapse into pagan worship.
ISAIAH 3:18- The Lord will take away. . . . their tinkling ornaments. . . and their cauls [beadbands, NIV], and their round tires like the moon [crescent necklaces, NIV]