I’ve had a thought.

In suzerain vassal treaties, two copies of the covenant were to be made (hence the two tablets of the Law), uniting suzerain and vassal and reminding them of their responsibilities. Vassals especially were expected to review their copy periodically. This fits well with the NT.

In the New Covenant, we do not have a written Law but a Savior who is the Word. He ascends into heaven to the right hand of the Father - the suzerain has his copy - and also leaves behind the Church-Body who receives, keeps, and teaches the Scriptures - the vassal has his copy.

In heaven, Jesus the Word is the "copy" of the treaty, possessed by the suzerain king, the Father; on earth, Jesus is the vassal king possessing his own "copy", the Church with her Scriptures - the Word and his Body are the two copies of the treaty.

The Scriptures are part of but not substantially or sufficiently the treaty: the Lord Jesus himself is, the Scriptures bearing testimony. And the Church is his copy of the treaty, as St. Paul says, the covenant is written "not on tablets of stone but on tablets of flesh."

He, through His Spirit in the liturgy and his appointed officers, "reviews" the treaty when the Scriptures are opened and He is known through them. He articulates himself to us through the Sacraments, homilies, hymnody, Creeds, and prayers.

This reminds us of our responsibilities and all to which we are beholden as citizens of the vassal-state under the suzerain to whom we owe allegiance. It helps direct us into conformity with the Word, the Divine "copy" of the treaty in whom we participate in the Spirit.