Deuteronomy 20:1-3

1When you go to war against your enemies and see horses and chariots and an army greater than yours, do not be afraid of them, because the Lord your God, who brought you up out of Egypt, will be with you.

2When you are about to go into battle, the priest shall come forward and address the army.

3He shall say: “Hear, Israel: Today you are going into battle against your enemies. Do not be fainthearted or afraid; do not panic or be terrified by them.