Why Esther Made Mordechai in Charge of Haman’s House

Why did Esther appoint Mordechai over the house of Haman?

R’ Avrohom Mordechai of Ger explains, that in the famous incident in which Mordechai and Haman were both in command of armies, Haman had to sell himself as a slave to Mordechai for food.

According to halachah: מה שקנה עבד קנה רבו - “Whatever a slave acquires becomes the property of his master” (Pesachim 88b). Consequently, in keeping within the realm of halachah, Esther conveyed the house to Mordechai, who in reality was the rightful owner.