Isaiah 3:4

And I will give children to be their princes, and babes shall rule over them.

Because Judah persisted in continued sin and transgression, God pronounced as judgment that children would be given to be princes and babes would rule over the people.
The children and babes mean both that the existing rulers had become like children and childlike in weakness, and that inexperienced, immature and unfit leaders would exercise authority.
That appointment reversed wise leadership and collapsed sound leadership into weakness and disorder.

This childish rule reflected the nation's dark condition, in which the forces for good were dwindling while evil was increasing.
It came through wickedness in high places and among those in power and those exercising authority.
It left Judah weak among other nations.

The prophecy also applies to the last days.
There its reproofs address the daughters of Zion who care only for appearance and display.
There its judgment will test young people who profess Christianity but lack Christian experience and personal responsibility.