What metaphors are used in A Testament of Hope: The Essential Writings and Speeches of Martin Luther King, Jr by Martin Luther King?

Nonviolent protests/actions/marches are metaphors for racial resistance and equaliry. Large group protests in which there was no violence on the part of the protesters. They willingly went to jail for breaking the law, and accepted the brutality of racist sheriffs in order to bring to public attention the injustices and indignities faced by the Southern Negro people.