Please help with homework Moby-Dick: Moby-Dick alternates between precise

Moby-Dick alternates between precise, often matter-of-fact descriptions of whaling and the extravagant, almost mythic actions of Ahab and his crew. Do these disparate elements enhance each other? If so, how so?

In “The Sermon,” Melville establishes the story of Jonah and the whale as a backdrop for Ahab’s later actions. How does Jonah’s story both parallel and provide a counterpoint to Ahab’s?