2 Chronicles 21:3 Commentary - English Annotations on the Holy Bible by Matthew Poole
Whom he conceived that he ought to prefer by virtue of that law of God, Deu 21:15, though otherwise he would not have done it, having probably ere this time perceived his perverse and wicked inclinations, and how much he was swayed by his idolatrous wife. Now he saw his error when it was too late.
Consult other comments:
2 Chronicles 21:3 - Albert Barnes' Notes on the Bible
2 Chronicles 21:3 - Joseph Benson’s Commentary on the Old and New Testaments
2 Chronicles 21:3 - The Cambridge Bible for Schools and Colleges
2 Chronicles 21:3 - Adam Clarke's Commentary and Critical Notes on the Bible
2 Chronicles 21:3 - John Gill's Exposition of the Entire Bible
2 Chronicles 21:3 - English Annotations on the Holy Bible by Matthew Poole
2 Chronicles 21:3 - 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.