In the eleventh year, on the first day of the third month, the word of the LORD came to me, saying,
This prophecy bears date the month before Jerusalem was taken, as that in the close of the foregoing chapter about four months before. When God's people were in the depth of their distress, it would be some comfort to them, as it would serve likewise for a check to the pride and malice of their neighbours, that insulted over them, to be told from heaven...
Commenting on Ezekiel 31:1-9
And it came to pass in the eleventh year,.... Of Zedekiah's reign, and Jeconiah's captivity: in the third month, in the first day of the month: the month Sivan, which began on the twentieth of our May, and answers to part of May, and part of June; this was about seven weeks after the former prophecy, and about five weeks before the destruction of Jerusalem...
And it came to pass in the eleventh year, in the third [month], in the first [day] of the month, [that] the word of the LORD came to me, saying, (a) Of Zedekiah's reign, or of Jeconiah's captivity.