Κύριος the Lord is used in Exo 34:34 for Jehovah. The Lord Christ of 2Co 3:16 is the Spirit who pervades and animates the new covenant of which we are ministers (2Co 3:6), and the ministration of which is with glory (2Co 3:8). Compare Rom 8:9-11; Joh 14:16, Joh 14:18.