2 Chronicles 20:15

15 And he said, "Listen, all you of Judah and you inhabitants of Jerusalem, and you, King Jehoshaphat! Thus says the Lord to you: 'Do not be afraid nor dismayed because of this great multitude, for the battle is not yours, but God's.

2 Chronicles 20:15 Meaning and Commentary

2 Chronicles 20:15

And he said, hearken ye, all Judah, and ye inhabitants of
Jerusalem, and thou King Jehoshaphat
There is a climax or gradation in these words rising from the lowest to the highest; from the people of the cities in the country, to the inhabitants of Jerusalem the metropolis, and from thence to the king the supreme governor: thus saith the Lord unto you, be not afraid, nor dismayed, by reason of
this great multitude;
whose numbers were discouraging to the king, and he had taken notice of them, which this respects: for the battle is not your's, but God's:
the cause was his, and he would espouse and maintain it; not they, but he, would fight the battle, and therefore they had nothing to fear.

2 Chronicles 20:15 In-Context

13 Now all Judah, with their little ones, their wives, and their children, stood before the Lord.

14 Then the Spirit of the Lord came upon Jahaziel the son of Zechariah, the son of Benaiah, the son of Jeiel, the son of Mattaniah, a Levite of the sons of Asaph, in the midst of the assembly.

15 And he said, "Listen, all you of Judah and you inhabitants of Jerusalem, and you, King Jehoshaphat! Thus says the Lord to you: 'Do not be afraid nor dismayed because of this great multitude, for the battle is not yours, but God's.

16 Tomorrow go down against them. They will surely come up by the Ascent of Ziz, and you will find them at the end of the brook before the Wilderness of Jeruel.

17 You will not need to fight in this battle. Position yourselves, stand still and see the salvation of the Lord, who is with you, O Judah and Jerusalem!' Do not fear or be dismayed; tomorrow go out against them, for the Lord is with you."