The correct answer is Walt Whitman
He says so in his poem I Sit and Look Out. The phrase is the final line of the poem.
Prose is the answer. Hope this helps! :)
In 1963, when Martin Luther King<span> Jr. delivered what is now known as </span>his<span> “</span>I Have a Dream<span>” </span>speech<span> on the steps of the Lincoln Memorial, he began not with utopian images of racial harmony — children holding hands, black and white breaking bread together — but with the </span>metaphor<span> of a bad check.</span>
