This is an unconditional covenant that God has declared He will make with the houses of Judah and Israel: He will put His laws into their minds and write them upon their hearts; He will be their God, and will be merciful to their unrighteousness, and remember their sins no more (Jer. 31:31-34). The foundation for this was laid in the cross. This is obscured in the AV by the word (διαθήκη) not being uniformly translated. Sometimes it is rendered “testament” and sometimes “covenant.” At the institution of the Lord’s supper the Lord spoke of His blood as “the blood of the new covenant” (Matt. 26:28; 1 Cor. 11:25); and “He is the mediator of the new covenant” (Heb. 9:15; Heb. 12:24). From which we gather that though the making of this covenant with Israel is still future, the principle of it, namely, that of sovereign grace, is that on which God is now acting as setting forth the terms on which He is with His people, the Lord Jesus being the Mediator, through whom all the blessing is secured. See inter alia Romans 5:1-10, and 2 Corinthians 3 where Paul speaks of himself and those with him as “able ministers of the new covenant,” not of the letter which killeth, but of the spirit which giveth life (2 Cor. 3:6). The word διαθήκη is better always translated “covenant,” except in Hebrews 9:16-17, where the “will or testament” of a man is referred to.