List two devices of repetition in "Song of Slaves in the Desert." Give examples and explain why Whittier used these devices.

Alliteration, anaphora

Explanation:

Alliteration is a literary device which presents repeating of first letters of the words in order to emphasize them and to create a special tone when we read it out loud, it is mostly used in poetry. Whittier used this device in order to to create that flowing melody, since it is a song of slaves it has to have a rhythm that follows their daily hard-work.

Strong the Ghiblee wind is blowing,  

Strange and large the world is growing ;

Anaphora is a literary device of repetition of the first word or words in successive lines, phrases or clauses so as to achieve sonic effect. Here in this poem is used to accentuate who are the of this fiendish journey and to stress their position, but not in geographical sense, but in a sense of their physical and mental state (they are hungry, tired, not sure where are they going, what to expect on this road, they highlight that he (God is the one who has the power to show them what is the right thing to do, also they are showing their sorrow and despair for leaving Bornou, their deific home).

We are blind, but Thou hast eyes  

We are fools, but Thou art wise! ;

Here we thirst and here we hunger,  

Here the Moor-man smites in anger ;

pulling in the reader is important