"As surely as Yahweh is alive." The people use this expression to show that what they say next is certainly true. This is a way of making a solemn promise. Swearing in Yahweh's name instead of in Baal's name indicates that they worship Yahweh instead of Baal. See how you translated this in [Jeremiah 4:2](../04/02.md). Alternate translation: "I solemnly swear" (See: [[rc://en/ta/man/translate/figs-idiom]])
This speaks of the people becoming prosperous as if they were a building that was being built. This can be stated in active form. Alternate translation: "I will build them up in the midst of my people" or "I will make them wealthy and they will live among my people" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])