2 Chronicles 20:5 Commentary - English Annotations on the Holy Bible by Matthew Poole

In the house of the Lord, largely so called, i.e. in one of the courts of the temple, even in the court of the people, and upon that brazen scaffold which Solomon had erected for such a purpose, 2Ch 6:13.

Before the new court, i.e. besides and before the priests’ court; for there were but two courts belonging to the temple, as is noted 2Ki 21:5; 23:12. And Jehoshaphat stood in the one, which must be that of the people; and before the other, which therefore can be no other than that of the priests’, which is called the new court, because it had been lately renewed when the altar was renewed, 2Ch 15:8, as the command of love is called a new command, Joh 13:34; 1Jo 2:8, because it was so solemnly renewed, and revived, and reinforced by Christ.