285. Since this law is the means of linking the Lord with man and man with the Lord, it is called a covenant and a testimony. It is called a covenant because it serves as a link, and a testimony because it establishes the terms of the covenant. For covenant in the Word means linking, testimony the establishment and witnessing of its terms. That is why there were two tablets, one for God and the other for man. The link is provided by the Lord, but only when man does what is written in his tablet. For the Lord is continually present, and wishes to enter; but man must open the door by the free will which the Lord gives him. For He says:
Behold, I stand at the door and knock. If anyone hears my voice and opens the door, I will come in to him and dine with him, and he with me. Rev. 3:20.
The stone tablets on which the law was written are called the tablets of the covenant, and the Ark is called from them the Ark of the covenant; the law itself is called the covenant: see Num. 10:33; Deut. 4:13, 23; 5:2, 3; 9:9; Josh. 3:11; 1 Kings 8:21; Rev. 11:19; and elsewhere.
Since a covenant means being joined, it is said of the Lord that He will be a covenant for the people (Isa. 42:6; 49:8); He is called the messenger of the covenant (Mal. 3:1); and His blood is called the blood of the covenant (Matt. 26:28; Zech. 9:11; Exod. 24:4-10). That is why the Word is called the Old and the New Covenants*, for covenants are made on account of love, friendship, association and linking.
* The author uses the correct Latin translation of the Greek word, which was erroneously translated into Latin in antiquity as testamentum, hence our Testament.