Explain the figurative language in the following quotation from paragraph 23. What is the
purpose of this comparison? "For that day Monsieur Hamel had prepared some entirely
new examples, on which was written in a fine, round hand: 'France, Alsace, France, Alsace.'
They were like little flags, waving all about the class, hanging from the rods of our desks."

The use of figurative language here is in the line:

They were like little flags, waving all about the class, hanging from the rods of our desks

Explanation:

The line here that shows the use of figurative language makes a comparison between the lines of words in French and their associations and they are compared to flags that are posted onto the rods of the desk of the classroom.

In this story Mr Hamel has his last class with the French kids and so the kids understand that it is the last time probably they will ever study the mother tongue.

Thus, every word of it becomes significant like a  flag that is posted upon their desk, as if to show its necessity.

i'm not good at running