Why does douglass include the poem by john greenleaf whittier after he tells the story about his grandmother?

In this narrative, Douglas includes the poem Whittier by John Greenleaf because it refers to slavery.

He related the poem to his grandmother's own experience, due to the fact that she was a slave and died blind.

Besides that, all the text refers to slavery in general.

The author makes several points about slavery such us:

-No one can be enslaved if he or she has the opportunity to think, read and write

- Justice for slaves is very different from justice for whites, among others

the examples that saki used to represent satire through situational irony are options two (2) and five (5) inasmuch as the wolf thought that looking for a girl in the bushes could be as easy as hunting little pigs at the park, but it took him so much time to find the girl if it had not been not for a silly mistake. also, bertha would have survived to the wolf's hunt if she had not won those medals for goodness, which at the end they were what got her killed by making noise, so winning medals of goodness was not so good achievement, after all.