Isaiah 55:3
3. me . . . live—by coming to me ye shall live: for "I am the life" (Joh 14:6).
everlasting covenant— (Jer 32:40; 2Sa 23:5). with you . . . David—God's covenant is with the antitypical David, Messiah (Eze 34:23), and so with us by our identification with Him. sure—answering to "everlasting," irrevocable, unfailing, to be relied on (Ps 89:2-4, 28, 29, 34-36; Jer 33:20, 21; 2Sa 7:15, 16; 2Co 1:18-20). mercies of David—the mercies of grace (Isa 63:7; Joh 1:16) which I covenanted to give to David, and especially to Messiah, his antitype. Quoted in Ac 13:34. Jeremiah 31:31
31. the days . . . new covenant with . . . Israel . . . Judah—The new covenant is made with literal Israel and Judah, not with the spiritual Israel, that is, believers, except secondarily, and as grafted on the stock of Israel (Ro 11:16-27). For the whole subject of the thirtieth and thirty-first chapters is the restoration of the Hebrews (Jer 30:4, 7, 10, 18; 31:7, 10, 11, 23, 24, 27, 36). With the "remnant according to the election of grace" in Israel, the new covenant has already taken effect. But with regard to the whole nation, its realization is reserved for the last days, to which Paul refers this prophecy in an abridged form (Ro 11:27).
Jeremiah 31:33
33. will be their God— (Jer 32:38).