(29, 30) The fathers have eaten a sour grape . . .--The proverb was one which, as we find from Ezekiel 18:2-3, had at this time come into common use. Men found in it an explanation of their sufferings which relieved their consciences. They were suffering, they said, for the sins of their fathers, not for their own. They distorted the words which, as asserting the continuity of national life, were attached to the second Commandment (Exodus 20:5), and instead of finding in them a warning restraining them from evil by the fear of transmitting evil to another generation, they found in them a plea for their own recklessness. Both Ezekiel and Jeremiah felt that the time was come when, even at the risk of a seeming contradiction to words clothed with a Divine authority, the other aspect of God's government had to be asserted in all its fulness: and therefore they lay stress on the truth that each man is responsible for his own acts, and for those alone, and that the law of the inheritance of evil (what we have learnt to call the law of heredite) leaves untouched the freedom of man's will. The "eater of the sour grape, his teeth shall be set on edge," is, as it were, an emendation of the proverbial saying. The words of the Latin poet, "Delicta majorum immeritus lues," "Thou, for no guilt of thine, shalt pay the forfeit of thy fathers' sins" (Hor. Od. iii. 6, 1), show how ready men have been at all times to make a like excuse. How the two truths are to be reconciled, the law of hereditary tendencies, and punishments that fall not on the original offenders, but on their children, and the law of individual responsibility, is a question to which we can give no formal answer. We must be content to accept both laws, and rest in the belief that the Judge of all the earth will assuredly do right.

Verse 29. - Have eaten a sour grape; rather, sour grapes. The prophet (like Ezekiel, ch. 18.) condemns the use of this proverb, and declares that the sinner is the artificer of his own ruin. At first sight, it may seem as if Jeremiah opposes the second commandment, which describes how God "visits the iniquity of the fathers upon the children" (Exodus 20:5). This, however, cannot really be, for he endorses this declaration later on (Jeremiah 32:18). The fact is that he is not so much condemning the proverb, as the blasphemous application of it made by the Jews of his time. It is an eternal truth that sin perpetuates itself (except by the miracles of grace) in the children of transgressors, and intensified sin leads to intensified punishment. But the children of transgressors do not cease to be responsible for their own share in the sin; - this was the truth which Jeremiah's contemporaries ignored. He does not deny the solidarity of the family or the race,but he superadds the neglected truth of the special responsibility of the individual. This is one among many evidences of the deepening sense of individual life in the later period of the Jewish monarchy. (A somewhat different view is offered by Delitzsch, 'Messianic Prophecies,' § 50. According to him, Jeremiah looks forward to a time when the individual shall be liberated from the consequences of his solidarity with his race, and when personality shall be "invested with its rights." But can the individual be thus liberated?)

31:27-34 The people of God shall become numerous and prosperous. In Heb 8:8,9, this place is quoted as the sum of the covenant of grace made with believers in Jesus Christ. Not, I will give them a new law; for Christ came not to destroy the law, but to fulfil it; but the law shall be written in their hearts by the finger of the Spirit, as formerly written in the tables of stone. The Lord will, by his grace, make his people willing people in the day of his power. All shall know the Lord; all shall be welcome to the knowledge of God, and shall have the means of that knowledge. There shall be an outpouring of the Holy Spirit, at the time the gospel is published. No man shall finally perish, but for his own sins; none, who is willing to accept of Christ's salvation.In those days they shall say no more,.... The following proverb or byword; they should have no occasion to use it, nor should they choose to use it; since they would understand themselves, and the dispensations of Providence towards them, better than to use it:

the fathers have eaten a sour grape, and the children's teeth are set on edge; that is, the fathers have sinned, and the children are punished for their sins. So the Targum,

"the fathers have sinned, and the children are smitten.''

This was in some sense true; they were punished for their fathers' sins in the captivity, particularly for Manasseh's; nor was it unusual with God to visit the iniquities of the fathers upon the children; nor at all unjust, since they were a part of their parents, and especially since they were guilty of the same sins; nor is it thought unjust among men to punish children for the treason of their parents, as every sin is treason against God. But this was not all that was meant by this proverb; the sense of those that used it was, that they themselves were quite clear and innocent, and that they only suffered for their fathers' faults; which was false, of which they should be convinced, and use the proverb no more, as charging God with injustice.