The concept of the holy war, declared, fought and won by Yahweh, God of Israel, originates in traditions of the God as a divine warrior which are found in the Hebrew Bible. In the Deuteronomic literature in particular a systematic ideology of holy war is laid out. In Joshua and Judges there are stories of Yahweh leading his people to victory in wars, mostly against the Canaan occupants of the promised land. Deuteronomy gives regulation for the ritual accompanying such a war, culminating in the devotion of a captured city to Yahweh and consequent annihilation of all its inhabitants. The fact Israel is confirmed by an inscription of Mesha, King of Moab, who describes the devotion of captured Israelite cities to the Moabite God Chemosh. Although certain features of the holy war must have been present in early Israel, it is likely that the detailed institution seen in Deuteronomy is a later interpretation. In the 2nd century BC the Maccabaeus Revolt took too many of the characteristics of a holy war, directed as it was against pagan overlords. Holy was also features prominently in much of the apocalyptic literature of the Old Testament where the final battle takes on cosmic proportions.
All Jewish wars were religious was, fought at the call of and on behalf of Elohim. Before battle there were religious ceremonies after consultation with the prophets. Scouts or spies were sent out ahead of the main force. The average battle was a straight forward test of strength and courage rather that skill, strategy and tactics. The two armies faced one another in line at a sign from the commanders and the advancement began. Prisoners were enslaved. Defeated nations had to pay indemnities. The wages of the victor was the plunder.