The term leben, variously laban, lben (Arabic: لبن) is used across the Arab World (Middle East and North Africa), to refer to a food or beverage of fermented milk. Generally, there are two main products known as leben: in the Levant region, yogurt; and in Arabia and North Africa (Maghreb), buttermilk. The practice of intentionally allowing milk to sour has been known since ancient times and practiced by many cultures.
Buttermilk drink
Leben as a drink is traditionally prepared by allowing milk to ferment for around 24 hours, then churning and removing the butter. The remaining buttermilk can keep for several days at room temperature. In modern times, it is produced industrially.
References
Leben (milk product) Wikipedia(Text) CC BY-SA