Many wonder why the Book of Esther is in the Bible, because the name of God is not mentioned in it. Yet actually, God is mentioned throughout the account. The main people in the book also are symbols for God, God’s Messiah, Israel and the Adversary, aka haSatan.
Many passages in the Bible were written with a chiastic structure, which is like rhyming patterns in poetry but pairing similar information or concepts instead. That’s one reason why some passages seem to be highly repetitive. The point of chiastic structures is to point the reader to a key concept. Daniel explains that the Book of Esther is one large chiastic structure, focusing on a messianic prophecy in the middle.