Neh 9:8

9:8 made with him the covenant. This covenant with Abraham (Gen. 15) is the basis upon which God’s grace is extended time and again to His unfaithful people, as is brought out in the remainder of this prayer of praise.

you have kept your promise. God’s promise to Abraham was conditioned only upon God’s righteous oath (Gen. 15:9–21; Deut. 9:4–6).