Bible Dictionary · L
Letter
In Rom 2:27, Rom 2:29 means the outward form. The “oldness of the letter” (Rom 7:6) is a phrase which denotes the old way of literal outward obedience to the law as a system of mere external rules of conduct. In 2 Cor 3:6, “the letter” means the Mosaic law as a written law. (See Writing.)
From Easton’s Bible Dictionary (1897), by Matthew George Easton.