"And it shall be when you come near to the battle, the priest shall approach"Deuteronomy 20:2.

We are commanded to appoint a priest who will deliver before the soldiers the "Battle Address." In this address he requests of those not suited for battle – whether due to physical or emotional frailty, or due to the fact that their minds are preoccupied with a matter that prevents them from properly focusing on the battle – to turn away. The people who must not proceed to the battlefield due to distraction are the three mentioned in the Torah: a) One who has built a home but not dedicated it. b) One who has planted a vineyard and not yet enjoyed its fruits. c) One who has betrothed a women but not married her.

This priest who addresses the soldiers is called the Mashuach Milchamah ("the one anointed for battle").

The priest's address is verbatim the words that the Torah (in Deuteronomy) instructs him to say. After saying the biblical lines, he adds words of his own, words to inspire the soldiers to courageously battle to bring victory for G‑d's religion, and to bring retribution upon the fools who destroy civilized society.

This address is spoken by the designated priest, and then loudly repeated by the military police.

All the above applies only to an "optional battle"; no speeches or proclamations are made before a "mitzvah battle" [e.g., the battle against Amalek or a self-defense battle].