Passage
In those days they do not say any more: Fathers have eaten unripe fruit, And the sons' teeth are blunted.
In those days they do not say any more: Fathers have eaten unripe fruit, And the sons' teeth are blunted.
Jeremiah 31:27 Lo, days are coming, an affirmation of Jehovah, And I have sown the house of Israel, And the house of Judah, With seed of man, and seed of beast.
Jeremiah 31:28 And it hath been, as I watched over them to pluck up, And to break down, and to throw down, And to destroy, and to afflict; So do I watch over them to build, and to plant, An affirmation of Jehovah.
Jeremiah 31:29 In those days they do not say any more: Fathers have eaten unripe fruit, And the sons' teeth are blunted.
Jeremiah 31:30 But--each for his own iniquity doth die, Every man who is eating the unripe fruit, Blunted are his teeth.
Jeremiah 31:31 Lo, days are coming, an affirmation of Jehovah, And I have made with the house of Israel And with the house of Judah a new covenant,
The verse centers on "days", "fathers", "eaten", "unripe", "fruit", "sons'", "teeth", and "blunted". It is saying that the verse draws attention to "days" and "fathers", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 28's "And it hath been as I watched..." into verse 30's "But--each for his own iniquity doth die...", so "days" and "fathers" belong inside that flow. In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "days" and "fathers" with trust shaped by these words, not by a vague optimism outside the passage.