Israel was not to worry about the power and strength of other nations. Instead, they were to trust in the power of Yahweh. He is the source of their military strength and protection. This is why a priest leads them into battle, rather than a military commander. (See: [[rc://en/tw/dict/bible/kt/trust]] and [[rc://en/tw/dict/bible/kt/priest]])
Israel's conquering of the Promised Land was unique in history. It was a type of holy war and had special rules. This war was really Yahweh's punishment against the sin of the Canaanite people. If the people were not completely destroyed, they would cause Israel to sin. (See: [[rc://en/tw/dict/bible/kt/promisedland]] and [[rc://en/tw/dict/bible/kt/holy]] and [[rc://en/tw/dict/bible/kt/sin]])
This phrase is used several times to introduce a rhetorical question. The questions are intended to tell the readers that Yahweh only wants soldiers who are completely dedicated to fighting for him. (See: [[rc://en/ta/man/jit/figs-rquestion]])
In ancient Israel, men were excused from fighting in battle for several different reasons. Some of these reasons are mentioned in this chapter. Apparently, needing to establish a new house, the need to harvest a field and cowardice were possible excuses. (See: [[rc://en/ta/man/jit/figs-explicit]])