Esther is purely historical among other manuscripts, as there's no "God" word mentioned in this book but you can see by understanding that God, is the main point in this story.
In verse 1-14, God has a good plan; and in verse 15-23, He will bless His people. Here in verse 1-4, the plan to look for a new Queen doesn't matter either rich or poor - can become a queen.
Citadel means place of refuge, fortress or a place to protect them. It's like taking a daily bath - to be cleanse by the word of God. One of the characteristics of Esther is being humble.
Hadassah is the other name of Esther. The picture of Mordecai here is just like God, in reality we are being Fatherless and he is taking the responsibility for Esther.
2 Corinthians 6:18 And,
“I will be a Father to you,
and you will be my sons and daughters, says the Lord Almighty.”
1 John 3:1 See what great love the Father has lavished on us, that we should be called children of God! And that is what we are! The reason the world does not know us is that it did not know him.
We can see here that God is working in us, He is faithful. Esther and Mordecai feared the Lord. As it teaches the inner beauty is the most important. We will receive crown of righteousness according to our works.
7 He raises the poor from the dust
and lifts the needy from the ash heap;
8 he seats them with princes,
with the princes of his people.
The picture of Esther here is obedience of love to God. Gallows is like a straight wood with a sharp-edge. Even in the midst of godless society, God put you there, and He is working in you.
Philippians 4:2 I plead with Euodia and I plead with Syntyche to be of the same mind in the Lord.
Perhaps you may think God is not working in you, but if you seek God's word and you will know God is working in your life.