Jeremiah pointed out to the people of his day their great fault. Actually two things. The text has God wondering just what He has done (or not done) 'what iniquity' they found in Him that caused them to turn to other gods. Iniquity is defined as injustice. What injustice has they found in Him. Have you ever felt that God failed you, or simply did not give you something you had earnestly prayed for? Have you ever felt life was unfair?
Those people were the children of Israel, known throughout the Biblical world as those who believed in one God. That was the first of the Ten Commandments God gave to Moses. So what happened? Jeremiah had been mourning his people's sins. Elijah and Elisha, prophets before him, had spoken only to the Hebrews. Jeremiah is speaking to all of us. He tells his hearers the grossness of their conduct in deserting Jeremiah, and urges repentance - a change of thought.
God's blessing is shown as fresh water supplied by a spring. It is contrasted with the vanity of serving idols, which is as devoid of profit as a cracked resevoir.
How often we are distressed when we stop leaning on the sustaining Infinite and put our faith in material sources, places where we have set aside funds. Without understanding the true source of supply, a continually refreshed living source, we can find our funds draining out, suddenly being needed for an emergency, and no matter how hard we try to build up that reserve, it keeps dwindling. Another thing to consider is that the cistern is made of clay, the dust of the ground. Putting our reliance there, even worshipping it more than God, puts us squarely in the second account of creation, man made from the dust of the ground and cursed to toil for a living.
Take some time to appreciate the infinitely flowing ideas of good. The living water God provides for us. Be careful not to rely on broken cisterns.
Be at peace.