Answer:
The effect of repetition on these lines is to intensify the meaning of the sentence.
Explanation:
Repetition is a picture of language that is closely related to the syntactic construction of the text. For this reason, it is called a syntax picture. This language picture occurs by repeating terms at the beginning of sentences. It is a stylistic resource widely used by writers in the construction of verses in order to intensify an expression described in the sentence. An example of this can be seen in the excerpt shown in the question, where the lines "Some visitor entreating entrance at my chamber door - Some late visitor entreating entrance at my chamber door;" intensify meaning, making the reader feel stronger during reading.
A deep fissure in earth, rock, or another surface
