Meaning: This sentence describes the mysterious and secretive connection between the ocean and the land, as the tide whispers hidden stories to the sand.
Choice of Words: "Tide" is the rising and falling of the sea level. "Whispers" means to speak very softly. "Secrets" are things that are kept hidden or private. "Sand" is the loose material on the beach. When you put them together, the sentence suggests that the rising and falling of the sea level quietly shares hidden things with the sand.