Albert Barnes Commentary 2 Chronicles 20:5

"And Jehoshaphat stood in the assembly of Judah and Jerusalem, in the house of Jehovah, before the new court;" — 2 Chronicles 20:5 (ASV)

The new court - In Solomon’s Temple there were two courts. One of these had probably been renovated by Jehoshaphat or by his father, Asa (2 Chronicles 15:8), and was known as “the new court.”