Matthew Henry on Jeremiah 17:1-4

The sins which men commit make little impression on their minds, yet every sin is marked in the book of God; they are all so graven upon the table of the heart, that they will all be remembered by the conscience. That which is graven in the heart will become plain in the life; men's actions show the desires and purposes of their hearts. What need we have to humble ourselves before God, who are so vile in his sight! How should we depend on his mercy and grace, begging of God to search and prove us; not to suffer us to be deceived by our own hearts, but to create in us a clean and holy nature by his Spirit!