Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why
LXX

2 Chronicles 20:17

It is not for you to fight: understand these things, and see the deliverance of the Lord with you, Juda and Jerusalem: fear not, neither be afraid to go forth to-morrow to meet them; and the Lord shall be with you.

Read in other translations