How does longfellow include elements of the story of sampson in "the warning"? he draws from the conflict between sampson and the philistines to highlight the pointlessness of seeking revenge. he uses unjust treatment of sampson by the philistines to draw attention to the plight of prisoners throughout history. he incorporates sampson’s faults as a person into his poem to caution readers about the consequences of vanity. he bases the message of his poem on what readers can learn from sampson’s uprising against the philistines.

The correct answer is: He uses unjust treatment of Sampson by the Philistines to draw attention to the plight of prisoners throughout history.

The author describes both Sampson's and the slave's plights in the story - the slave being discussed in the first two paragraphs, and Sampson being introduced at the last one. Moreover, both these two characters' conditions are presented in a similar manner: They are poor, blind and have been shorn of their strenghts - with Sampson being additionally eager to break his bonds.

The slave in the story is a poetic description of the suffering of every prisoner that has ever existed, and Sampson is included in this characterization as to highlight the prisoner's desire to escape.