Read Isaiah 9:3 Using Other Translations
Thou hast multiplied the nation, and not increased the joy: they joy before thee according to the joy in harvest, and as men rejoice when they divide the spoil.
You have multiplied the nation; you have increased its joy; they rejoice before you as with joy at the harvest, as they are glad when they divide the spoil.
You will enlarge the nation of Israel, and its people will rejoice. They will rejoice before you as people rejoice at the harvest and like warriors dividing the plunder.