Albert Barnes Commentary Jeremiah 31:27-34

"Behold, the days come, saith Jehovah, that I will sow the house of Israel and the house of Judah with the seed of man, and with the seed of beast. And it shall come to pass that, like as I have watched over them to pluck up and to break down and to overthrow and to destroy and to afflict, so will I watch over them to build and to plant, saith Jehovah. In those days they shall say no more, The fathers have eaten sour grapes, and the children`s teeth are set on edge. But every one shall die for his own iniquity: every man that eateth the sour grapes, his teeth shall be set on edge. Behold, the days come, saith Jehovah, that I will make a new covenant with the house of Israel, and with the house of Judah: 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. But this is the covenant that I will make with the house of Israel after those days, saith Jehovah: I will put my law in their inward parts, and in their heart will I write it; and I will be their God, and they shall be my people: and they shall teach no more every man his neighbor, and every man his brother, saying, Know Jehovah; for they shall all know me, from the least of them unto the greatest of them, saith Jehovah: for I will forgive their iniquity, and their sin will I remember no more." — Jeremiah 31:27-34 (ASV)

The prophet shows that the happiness of Israel and Judah, united in one prosperous nation, will rest upon the awareness that their discipline has been the result of sins they have themselves committed, and that God’s covenant depends not upon external sanctions, but upon a renewed heart.

(Jeremiah 31:27)

So rapid will be the increase that it will seem as if children and young cattle sprang up out of the ground.

(Jeremiah 31:29, Jeremiah 31:30)

A sour grape - Better, sour grapes. The idea that Jeremiah and Ezekiel modified the terms of the second Commandment arises from a mistaken interpretation of their words (Deuteronomy 24:16). The stubborn Jews made it a reproach to divine justice that the nation was to be severely punished for Manasseh’s sin. But this was only because generation after generation had, instead of repenting, repeated the sins of that evil time, and even in a worse form. Justice must finally have its course. The acknowledgment that each man died for his own iniquity was a sign of their return to a more just and right state of feeling.

(Jeremiah 31:31)

A time is foretold which will be to the nation as marked an epoch as was the Exodus. God at Sinai made a covenant with His people, the sanctions of which were material, or (where spiritual) materially understood. Therefore, the Mosaic Church was necessarily temporary, but the sanctions of Jeremiah’s Church are spiritual—written in the heart—and therefore it must take the place of the former covenant (Hebrews 8:13) and will last forever. The prophecy was fulfilled when those Jews who accepted Jesus of Nazareth as the Messiah expanded the Jewish into the Christian Church.

(Jeremiah 31:32)

Although ... - That is, although as their husband (or, "lord" (Baal, compare Hosea 2:16)) I had lawful authority over them. The translation in Hebrews 8:9 agrees with the Septuagint here, but the balance of authority favors the King James Version.

(Jeremiah 31:33)

The old law could be broken (Jeremiah 31:32); to remedy this God gives, not a new law, but a new power to the old law. It was formerly a mere code of morals, external to individuals, and obeyed out of duty. In Christianity, it becomes an inner force, shaping an individual's character from within.

(Jeremiah 31:34)

I will forgive their iniquity - The foundation of the new covenant is the free forgiveness of sins . It is the sense of this full, unmerited love which so deeply affects the heart as to make obedience henceforth an inner necessity.