The Hebrew text of the Book of Esther ends with verse 10:3. When Jerome created the Vulgate Bible, he added the Greek additions from
the Septuagint at the end of the Hebrew text, rather than place them in their proper context. In the notes, I'll mention where the additions
originally were in the Greek text.
This passage interprets the dream of Mordecai in 11:2 - 12.6, which formed the beginning of the Greek version of Esther.
(10:4) "God hath done these things."
The apocrypha to the rescue! The original (Hebrew) book of Esther was completely godless, so the genocides arranged by Esther and Mordecai (Mardochai in the Douay-Rheims)
could not be attributed to God. But the first line of the apocryphal text takes care of that: "God hath done all these things." (Who else would be so damned nasty?)
10:8 The nations that were assembled are they that endeavoured to destroy the name of the Jews.
10:9 And my nation is Israel, who cried to the Lord, and
the Lord saved his people: and he delivered us from all evils,
and hath wrought great signs and wonders among the nations:
10:10 And he commanded that there should be two lots, one of the people of God, and the other of all the nations.
10:11 And both lots came to the day appointed already from that time before God to all nations:
10:12 And the Lord remembered his people, and had mercy on his inheritance.
10:13 And these days shall be observed in the month of Adar on the fourteenth, and fifteenth day of the same month. with all diligence, and joy of the people gathered into one assembly,
throughout all the generations hereafter of the people of Israel.