This is deeper: what is the explanation of "treating turtles with ridicule"?

Wait: Wait.

Yarrow: yarrow, an ancient grass used for divination.

Tortoise: Tortoise shell. In ancient times, tortoise shells were baked with fire, and then the lines after baking were used to predict good or bad luck.

Laughing at a turtle means why wait for the result of divination! The result of metaphor is very clear, obvious, very clear, and you don't need to bother to analyze and think.