John Wesley on Jeremiah 31:33

With - That is, with those who are Jews inwardly. And write it - The prophet's design is here to express the difference betwixt the law and the gospel. The first shews duty, the latter brings the grace of regeneration, by which the heart is changed, and enabled for duty. All under the time of the law that came to salvation, were saved by this new covenant; but this was not evidently exhibited; neither was the regenerating grace of God so common under the time of the law, as it hath been under the gospel.