“The sin of Judah is written with an iron stylus, engraved with a diamond point on the tablets of their hearts and on the horns of their altars.
Jewish Publication Society of America Version (JPS1917) - Jeremiah 17:1 >The sin of Judah is written with a pen of iron, and with the point of a diamond; it is graven upon the tablet of their heart, and upon the horns of your altars.