Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[43] These proceedings of the people of those countries occasioned perplexity and trouble to Moses, who expected no such warlike preparations. And when these nations were ready to fight, and the multitude of the Hebrews were obliged to try the fortune of war, they were in a mighty disorder, and in want of all necessaries, and yet were to make war with men who were thoroughly well prepared for it. Then therefore it was that Moses began to encourage them, and to exhort them to have a good heart, and rely on God's assistance by which they had been state of freedom and to hope for victory over those who were ready to fight with them, in order to deprive them of that blessing: that they were to suppose their own army to be numerous, wanting nothing, neither weapons, nor money, nor provisions, nor such other conveniences as, when men are in possession of, they fight undauntedly; and that they are to judge themselves to have all these advantages in the Divine assistance. They are also to suppose the enemy's army to be small, unarmed, weak, and such as want those conveniences which they know must be wanted, when it is God's will that they shall be beaten; and how valuable God's assistance is, they had experienced in abundance of trials; and those such as were more terrible than war, for that is only against men; but these were against famine and thirst, things indeed that are in their own nature insuperable; as also against mountains, and that sea which afforded them no way for escaping; yet had all these difficulties been conquered by God's gracious kindness to them. So he exhorted them to be courageous at this time, and to look upon their entire prosperity to depend on the present conquest of their enemies.