The Laws concerning War

201 'When thou goest out to battle against thine enemy, and hast seen horse and chariot—a people more numerous than thou—thou art not afraid of them, for Jehovah thy God 'is' with thee, who is bringing thee up out of the land of Egypt; 2 and it hath been, in your drawing near unto the battle, that the priest hath come nigh, and spoken unto the people, 3 and said unto them, Hear, Israel, ye are drawing near to-day to battle against your enemies, let not your hearts be tender, fear not, nor make haste, nor be terrified at their presence, 4 for Jehovah your God 'is' He who is going with you, to fight for you with your enemies—to save you. 5 'And the authorities have spoken unto the people, saying, Who 'is' the man that hath built a new house, and hath not dedicated it?—let him go and turn back to his house, lest he die in battle, and another man dedicate it. 6 'And who 'is' the man that hath planted a vineyard, and hath not made it common?—let him go and turn back to his house, lest he die in battle, and another man make it common. 7 'And who 'is' the man that hath betrothed a woman, and hath not taken her?—let him go and turn back to his house, lest he die in battle, and another man take her. 8 'And the authorities have added to speak unto the people, and said, Who 'is' the man that is afraid and tender of heart?—let him go and turn back to his house, and the heart of his brethren doth not melt like his heart; 9 and it hath come to pass as the authorities finish to speak unto the people, that they have appointed princes of the hosts at the head of the people.

Matthew Henry's Commentary on Deuteronomy 20:1-9

Commentary on Deuteronomy 20:1-9

(Read Deuteronomy 20:1-9)

In the wars wherein Israel engaged according to the will of God, they might expect the Divine assistance. The Lord was to be their only confidence. In these respects they were types of the Christian's warfare. Those unwilling to fight, must be sent away. The unwillingness might arise from a man's outward condition. God would not be served by men forced against their will. Thy people shall be willing, Isaiah 8:12.