2 Corinthians 3:3 - Matthew Poole's English Annotations on the Holy Bible

He had told them before that they were his epistle, his epistle recommendatory, the change which God had wrought in their hearts did more recommend him than all the epistles in the world could; but here he tells them that they were the epistle of Christ, it was Christ that wrote his law in their hearts, (which writing was that which commended the apostle, who himself had but a ministration in the work), nor was it a writing with ink, but the impression of the Spirit of the living God. An epistle not written in tables of stone, but in the fleshy tables of the heart: he alludeth to the writing of the law, which was written in tables of stone, Exodus 31:18, and also to the promises, Ezekiel 11:19 Ezekiel 36:26. That work of grace in the hearts of these Corinthians, which recommended the apostle, was wrought by Christ, and the apostles were but ministers in the working of it; it was a work more admirable than the writing of the law in tables of stone, and this work (he saith) was manifestly declared.