"to save you": from snakes, scorpions, and adverse winds.
Thus far the Cohein anointed for war speaks; from this point on, the officers.
(whether he has betrothed a virgin or a widow, even one awaiting levirate marriage, and even if he has heard that his brother died in the war, he returns.)
All of them (the returnees) heed the words of the Cohein at the battle formation and return and supply water and food for their brothers and repair the roads.
Thus far the Cohein anointed for war speaks; from this point on, the officers. I might think (that they speak) their own words, but (8) "Then the officer shall speak further" already speaks of their own words. How, then, are we to understand "Then the officers shall speak"? As referring to the words of the Cohein appointed for war. How so? The Cohein spoke and an officer relayed what he said.