Charles Ellicott Commentary 2 Chronicles 36:11

"Zedekiah was twenty and one years old when he began to reign; and he reigned eleven years in Jerusalem:" — 2 Chronicles 36:11 (ASV)

ZEDEKIAH AND THE FINAL CATASTROPHE (2 Chronicles 36:11–21). (Compare to 2 Kings 24:18-25:21; Jeremiah 39; Jeremiah 52; Jeremiah 3; 1 Esdras 1:44-55.)

Zedekiah was twenty-one. —Likewise, 2 Kings 24:18 adds his mother’s name (Hamutal, who was also the mother of Jehoahaz).

Before Jeremiah ... mouth of the Lord. —Not in Kings. (Compare to Jeremiah 21; Jeremiah 22:1–10; Jeremiah 27; Jeremiah 28; Jeremiah 32-34; Jeremiah 37; Jeremiah 38)

Two special sins of Zedekiah are mentioned in this and the next verse—namely, his disregard of Jeremiah’s counsel, and his perjury to Nebuchadnezzar.