Charles Ellicott Commentary Jeremiah 31:32

"not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt; which my covenant they brake, although I was a husband unto them, saith Jehovah." — Jeremiah 31:32 (ASV)

Not according to the covenant ... — Our familiarity with the words hinders us, for the most part, from recognizing what must have seemed their exceeding boldness: that the Covenant with Israel, given with all conceivable sanctions as coming directly from Jehovah (Exodus 24:7–8), should thus be set aside, as a human repeals an earthly law—and the man who could say this without trembling must indeed have been confident that he too was taught by God, and that the new teaching was higher than the old.

Although I was an husband unto them. — The words declare the ground on which Jehovah might well have looked for the allegiance of Israel. (See Notes on Jeremiah 2:2; Jeremiah 3:20.)