As Yahweh lives

This is an idiom. "As certainly as Yahweh lives" or "This is a true statement" (See: rc://en/ta/man/jit/figs-idiom)

your going out and your coming in with me in the army is good

"I am happy to have you go out and come in with me and my army" or "It is good that you go everywhere with me and my army"