In Jeremiah, chapter seventeen, verse one, “The sin of Judah is written with a pen of iron, and with the point of a diamond: it is graven upon the table of their heart, and upon the horns of your altars.” Jeremiah indicts the nation for its great wickedness. The people’s sin was so deeply etched into their nature that idolatry and evil had become an integral part of their lives; for their infidelity, they would lose their land and become slaves, as in verse four. “And thou, even thyself, shalt discontinue from thine heritage that I gave thee: and I will cause thee to serve thine enemies in the land which thou knowest not: for ye have kindled a fire in mine anger, which shall burn forever.”
“A pen of iron” in this theme verse is a graving tool, chiefly used for engraving in stone or metal, in which this expression is also used in Psalm forty-five, verse one. “With the point of a diamond” expresses the idea of the hardness rather than the brilliancy of this jewel.
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 their conscience. That which is graven in their heart will become plain in their life. Men’s actions show the desires and purposes of their hearts. What need we all have to humble ourselves before God, who is so vile in his sight! How would 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!