Jeremiah 9:21

And by way of explanation he adds, For death has ascended into our windows There is here a kind of derision; for the Jews, as it has been said, had falsely promised to themselves a perpetual impunity; and therefore the Prophet adopts here a most suitable comparison. For as they sleep securely, who with closed doors seem to themselves to be beyond the reach of danger; so the Jews at that time despised God and all his judgments, as though the doors of their houses were closed. Hence the Prophet says, that death had entered in through the windows; and he thus derides their folly for thinking that they could escape the hand of God, because their gates were shut, as though. God’s power could not ascend above the clouds nor enter through their windows, when the doors were closed. In short, he intimates that the doors would not be opened by God; for though he might not be disposed to break them, he could yet immediately ascend into the windows. We now apprehend the Prophet’s design in saying, that death had entered through the windows.

And what he adds respecting palaces bears the same import; as though he had said, “Were our houses even fortified, and were they not. only commodious habitations, but made like citadels, yet God could not be excluded; for his power can penetrate through the highest and the thickest walls, so that a palace is to him like the weakest and frailest cottage.” We hence see that by this comparison he checks that foolisll confidence by which the Jews had deceived themselves, and by which they were as yet inebriated. Death then has ascended into our windows, etc.

He then adds,To cut off the young, or children, from the public ways, and the youths from the streets (253) By these words he sets forth the dreadfulness of the calamity; for the youths would not be able to defend themselves by their own strength; for by בחורים, bechurim, he means the most robust. Even these would not be able to repel the onset of their enemies; though in the flower of their age, yet their rigor, however strong, would not protect them, nor would children and infants be spared. We see that two things are here set forth by the Prophet, — that the assaults of their enemies would be so violent, that young men would in vain resist them, as their vigor would avail them nothing, — and then that such would be the cruelty of their enemies, that no regard would be shewn for age, for they would put to death even infants newly born. It follows —

For climbed has death through our windows, It has come through our towers,
To cut off the child from the street, The young men from the broad streets.

Though the gates were closed, yet death came in, not only through windows, or any openings there might have been, but also through strong towers. — Ed.