פּירוש אויף אסתר 5:3

Up until half the empire. A thing that is in the middle and at the halfway mark of the empire; that is, the Beis Hamikdosh, which they started to build in the days of Koresh, and he reneged and commanded to discontinue the work.³See Maseches Megillah 15b. And Achashveirosh, who succeeded him, he too discontinued the work. The simple meaning of the verse is, “Even if you request half of the empire from me, I will give it to you.”