In the eleventh year of Zedekiah, in the fourth month, on the ninth day of the month, a breach was made in the city.
It then follows, In the eleventh year, in the fourth month, the city was broken up We hence see that the city was besieged for a year and half; for there was the whole of the tenth year, and then added must be two months of the ninth year and four months of the eleventh year; and thus a year and half was the whole time.
We were told, in the close of the foregoing chapter, that Jeremiah abode patiently in the court of the prison, until the day that Jerusalem was taken. He gave the princes no further disturbance by his prophesying, nor they him by their persecutions; for he had no more to say than what he had said, and, the siege being carried on briskly, God found them other work to do.
Commenting on Jeremiah 39:1-10
And in the eleventh year of Zedekiah, in the fourth month,.... The month Tammuz, which answers to part of June, and part of July: the ninth day of the month, the city was broken up; or taken by storm; the walls of it were broken by engines and battering rams, so that the Chaldeans could enter it, and take it.