Pick a proverb you like – here is a web resource to start you off. https://www.phrases.org.uk/meanings/proverbs.html
Your task is to either
a) Write a passage where your character uses this proverb
b) Or write a scene to explain or deny the essence of this proverb.
While writing the scene think about whether the narrator / writer believes in the proverb or are they in contrast to their character who believes in them.
Think about whether your entire story / book can be reduced to a proverb! What are you saying in your story?