Sonnet XVIII, like the Bible, can be divided into two substantive parts. This division is indicated by the dividing line “Their moans / The Vales redoubl’d to the Hills, and they / To Heav’n.” This paper thinks that the tone of the Old Testament parallels the first division in which the immediate event is associated with the desire for vengeance. The God of the first part is a God of vengeance, an Old Testament Jehovah, invoked by the true believer for terrible retribution upon the oppressors of the chosen people.
Especially, biblical imagery in Jeremiah is used quite often in this sonnet; almost every expression can find an antecedent verse in Jeremiah, either in thought, structure or language. There are several reasons that explain why Milton probably had Jeremiah in mind throughout the sonnet. The prophet of the Old Testament, like Milton himself, stood apart from his people much of his life and at great cost to himself gave them an unpopular message. Often he opposed the entire nation and was found sitting alone, despised and rejected. Because he was alone, Jeremiah could take no physical action against what he knew to be wrong, but applied his bold message to try to awaken the people.
However, this paper believes that from “Their martyr’d blood and ashes sow / O’er all th’ Italian fields,” the sonnet begins to resolve as the poet recognizes, beyond Jeremiah, the New Testament God, who brings good out of evil. The echoes of Jeremiah in the sonnet become overshadowed by the language of the New Testament and the predominant Christian thought.