" If you give me a tear, I'll see all the oceans in your heart." What did that mean?

This sentence came from a poem in the online literature Sword Snow Stride ". The original text was " If you give me a tear, I will see all the oceans in your heart." It meant that if someone gave you a tear, you would be able to see all the emotions and thoughts in the depths of that person's heart. This sentence expressed a kind of deep emotion, meaning that the other party could give you support and comfort under certain circumstances, allowing you to feel the deep sea of emotions in your heart.