2 Chronicles 27:3 Commentary - English Annotations on the Holy Bible by Matthew Poole
He built, i.e. repaired it; for it was built before, 2Ch 11:5.
The high gate, otherwise called the new gate, Jer 36:10.
The wall of Ophel; a tower upon or near the wall of Jerusalem, which probably he fortified, as his father had done other towers, 2Ch 26:9.
Consult other comments:
2 Chronicles 27:3 - Albert Barnes' Notes on the Bible
2 Chronicles 27:3 - The Cambridge Bible for Schools and Colleges
2 Chronicles 27:3 - Adam Clarke's Commentary and Critical Notes on the Bible
2 Chronicles 27:3 - Commentary on the Holy Bible by Thomas Coke
2 Chronicles 27:3 - Companion Bible Notes, Appendices and Graphics
2 Chronicles 27:3 - Ellicott's Commentary for English Readers (Old and New Testaments)
2 Chronicles 27:3 - Geneva Bible Notes
2 Chronicles 27:3 - John Gill's Exposition of the Entire Bible
2 Chronicles 27:3 - Hawker's Poor Man's Commentary (Old and New Testaments)
2 Chronicles 27:3 - Biblical Illustrator Edited by Joseph S. Exell
2 Chronicles 27:3 - Keil & Delitzsch Commentary on the Old Testament
2 Chronicles 27:3 - English Annotations on the Holy Bible by Matthew Poole
2 Chronicles 27:3 - John Trapp's Complete Commentary (Old and New Testaments)
English Annotations on the Holy Bible by Matthew Poole

Matthew Poole (1624–1679) wrote English Annotations on the Holy Bible, completing the chapters as far as Isaiah 58 before his death in 1679. The rest of the Annotations were completed by friends and colleagues among his Nonconformist brethren. The first printing of the completed edition was in 1685, 2 volumes folio, followed by editions in 1688, 1696 (with valuable chapter outlines added by the editors, Samuel Clark and Edward Veale), and the 4th and definitive edition in 1700, the basis of all others.