One piece of figurative language is Martin Luther King saying,¨If I had sneezed,¨ meaning it is a metaphor and it really means that if he sneezed he would have not had his dream come true.
At the beginning,Martin Luther King got a Letter and it meant something to him because it came from a white girl and she was glad that he did not sneeze because she actually cared about him.
One of the themes in"I have been on the Mountaintop," is,never judge a person based on their color,due to the fact that white people were Mean to African American people.