'Letter' in the Bible

And they, by their keeping of the law without circumcision, will be judges of you, by whom the law is broken though you have the letter of the law and circumcision.

But he is a Jew who is a secret one, whose circumcision is of the heart, in the spirit and not in the letter; whose praise is not from men, but from God.

But now we are free from the law, having been made dead to that which had power over us; so that we are servants in the new way of the spirit, not in the old way of the letter.

I, Tertius, who have done the writing of this letter, send love in the Lord.