“kidneys...heart.” The “kidneys” refers to a person’s emotional life. The Word of God points to the fact that our kidneys, bowels, and belly (or womb) are part of our mental/emotional life, not “just physical organs.” Our “gut,” including our intestines, bowels, kidneys and stomach contain as many nerve cells as our brain, and studies are now showing that our “gut” contributes significantly to our emotional life and health. In contrast, in the biblical world, the “heart” refers to the thoughts, not the emotions.
Jeremiah, the writer of Lamentations, is emotionally distressed because of all the trouble and disaster that is happening in his world. [For more on the heart referring to the thought life, see commentary on Prov. 15:21. For more on kidneys referring to the emotional life, see commentary on Rev. 2:23, “kidneys”].