WCF 7.4.
This covenant of grace is frequently set forth in Scripture by the name of a testament, in reference to the death of Jesus Christ the Testator, and to the everlasting inheritance, with all things belonging to it, therein bequeathed. (Heb. 9:15–17, Heb. 7:22, Luke 22:20, 1 Cor. 11:25)