The differences between Isa 59:21 and Jer 31:31–34 make it unlikely that the Isaianic author is directly interacting with Jeremiah, though both passages speak of a future divine covenant. This covenant is alluded to in a number of passages in Isa 40–66 and is linked to several other major Isaianic themes, such as the servant of Yhwh, justice, and the final state of salvation. God’s promise of a covenant (59:21) applies only to those in Jacob who turn from their acts of injustice (59:20). The servant of Yhwh is the meditator of the covenant (42:6; 49:8), and this everlasting covenant (55:3; 61:8) will secure lasting blessings for the sons of Zion, the servants of Yhwh (54:13, 17). Their reception of God’s spirit and the placing of God’s word in their mouth will enable God’s people to obey his instructions (59:21) and enjoy the state of salvation described in chapters 60–62.