God calls himself a source of living, that is, running water. He is the God who lives and gives life. He provides everything that his people need in this world; and this source never dries up. But the people did not go to this well. Instead they hewed out cisterns for themselves to receive rainwater, but those cisterns could not hold the water. The water inside also became dirty and unclear. This refers to the idols. They seem like they have a lot to give, but in the end they always disappoint. In fact, in this way Israel has exchanged life for death, while it was not at all necessary, because the Source of living water is always present!
13 for my people have committed two evils: they have forsaken me, the fountain of living waters, and hewed out cisterns for themselves, broken cisterns that can hold no water.