Animal skins with the openings (orifices) sealed have been used for over 5,000 years for the drawing of water, transportation of liquids (water, wine, milk, etc.) and for the “churning” of milk products.
Mary is on the “business end” of a live churn in the Arab village of Mukmas (biblical Michmash, ca. 1974), located 7.5 mi. [12 km.] north of Jerusalem. This type of churn is an animal skin that has its orifices sealed and that has been filled with goat’s milk. It is then rocked back and forth as it is suspended on the tripod.
Here is a modern animal skin displayed at the open-air museum at Katzrin on the Golan Heights.
In ancient times even pottery vessels were modeled after these churns/liquid carriers.