II Corinthians 3:1-3 NKJV
Do we begin again to commend ourselves? Or do we need, as some others, epistles of commendation to you or letters of commendation from you? You are our epistle written in our hearts, known and read by all men; clearly you are an epistle of Christ, ministered by us, written not with ink but by the Spirit of the living God, not on tablets of stone but on tablets of flesh, that is, of the heart.
NKJV: New King James Version