Answer:
Assonance
Step-by-step explanation:
Assonance is a literary device where author uses the same or similar vowel which repeats in one line. Assonance is being used mostly in poetry in order to give the poem rhythm and musical effect.
In this particular example, we may notice assonance in the sound of /a/ being repeated in several words (“May be refin'd, and join th' angelic train.”)