"More than any other text in the Old Testament, Esther asks us to read it in light of the canon Scripture. One could contend that we look for God in Esther only because its place within the Old Testament compels us to read it religiously, seeking theological themes because the nature of the canon leads us to look for what is not otherwise there. But this is a cynical view of the canon, and even in considering the book's main characters it has been impossible to avoid reference to other parts of the Old Testament. Thus, the introductions to both Mordecai and Haman direct us to 1 Samuel, and then to Exodus 17 to understand the conflict between Israel and Amalek. Esther and Haman respectively embody the wise and fool from Israel's wisdom traditions, though without thereby becoming ciphers for these figures. They remain responsible individuals, yet their stories are told so that those who know the wisdom traditions cannot help but note the connections. Once we realize that so much of the story is told in a way that alludes to other passages in the Old Testament we begin to realise that our reading of Esther is meant to be shaped by what we know from these other passages and these allusions are consistently theological in their emphases."
David G. Firth, The Message of Esther, Bible Speaks Today, ed. J. A. Motyer (Downers Grove: InterVarsity, 2010), 33-4.