Albert Barnes Commentary Jeremiah 13:17

"But if ye will not hear it, my soul shall weep in secret for [your] pride; and mine eye shall weep sore, and run down with tears, because Jehovah`s flock is taken captive." — Jeremiah 13:17 (ASV)

The Lord’s flock - The people carried away captive with Jeconiah formed the Jewish Church, as we are expressly told, whereas Zedekiah and the people of Jerusalem possessed only the externals of the Church and not its reality. It is for this reason that the seventy years’ exile counts from Jeconiah’s captivity.