How did unusual events in Mesopotamia become omens of future danger?

In ancient Mesopotamia, unusual events were interpreted as omens because they were viewed as "symptoms" of the future, much like a physician identifies the onset of a disease. Rather than being purely theological, this form of divination was an attempt to read the future from signs present in the natural or social world.1

For example, if a desert plant sprouted within a city, it was interpreted as a sign that the "desert essence" was encroaching, which served as an omen that the city would be laid waste. These unusual happenings were believed to be messages from the gods, who might take the initiative to convey their will or warn of future dangers through such portents.1

This practice was highly systematized, particularly in astrology, where celestial phenomena—such as eclipses, planetary movements, and meteorological events—were carefully recorded in handbooks to correlate with terrestrial events and national fates. Through these observations, Mesopotamian priests sought to understand the divine will and determine the future of their community.213