'Tablets' in the Bible

Then Moses turned and went down from the mountain with the two tablets of the Testimony in his hand; tablets that were written on both sides—they were written on one side and on the other.

The sin of Judah is written down with an iron stylus;With a diamond point it is engraved upon the tablet of their heartAnd on the horns of their altars.

Then the Lord answered me and said,“Write the visionAnd engrave it plainly on [clay] tabletsSo that the one who reads it will run.

You show that you are a letter from Christ, delivered by us, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts.