Jeremias 4:4

Circumcise yourselves to the Lord. — The words show that the prophet had grasped the meaning of the symbol which to so many Jews was merely an outward sign. He saw that the “foreskin of the heart” was the fleshly, unrenewed nature, the “flesh” as contrasted with the “spirit,” the “old man” which St. Paul contrasts with the new (Romanos 6:6; Romanos 8:7). The verbal coincidence, with Deuteronômio 10:16; Deuteronômio 30:6 shows the influence of that book, of which we find so many traces in Jeremiah’s teaching.

Lest my fury come forth like fire... — The words, which describe the righteousness of Jehovah as a consuming fire, have their parallel in Jeremias 7:20; Amós 5:6, and form the transition to the picture of terror which opens in the next verse.