2 Chronicles 20:3 Commentary - English Annotations on the Holy Bible by Matthew Poole
Jehoshaphat feared; partly from human frailty, and partly from the remembrance of his own guilt, and the wrath of God denounced against him for it, 2Ch 19:2.
Set himself to seek the Lord: the phrase notes his settled resolution, seriousness, and earnestness in it, and the preparing and fixing his heart for it.
Proclaimed a fast; partly in token of his humiliation and penitence for his sins, and partly to make himself and his people more fervent in their prayers.
Consult other comments:
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.