Jeremiah 6:7 says of Jerusalem, “As a well keeps cold its waters, so shee keeps cold her wickedness.”

Cities are wells.  How?  Visually there is a resemblance: Walls enclose a city as walls enclose the shaft of a well.  No doubt too there is a third term in the comparison: Women are wells, cities are feminine, and therefore wells are cities.  But in Jeremiah, the accent is on what wells and cities might contain.  People went to wells in ancient Israel to get water, and so people might go to a city to find the necessities of life.  Water bubbles up inside a well, and flows out, and a city also always has an outflow.  Living water flows from some cities (like the bride-city of Revelation), but from Jerusalem in Jeremiah’s day there comes only “fresh” wickedness, destruction, and violence.