The Kudurru

Something interesting appeared during this time, and object called a Kudurru. It was a large stone with inscribed details of land grants that were grants of tax exemption on land. Most of the Kudurru were actually large boundary stones bearing the symbols of the deities, which were invoked in the text to guard from terrestrial encroachment. [Middle Babylonian Period] Bible History Online

Link: https://bible-history.com/babylonia/the-kudurru