The word "stood" is understood from the previous phrase. Alternate translation: "the Levites also stood with instruments of music of Yahweh" (See: [[rc://en/ta/man/jit/figs-ellipsis]])
The abstract noun "faithfulness" can be stated as "faithfully" or "faithful." See how you translated "covenant faithfulness" in [2 Chronicles 7:3](../07/03.md). Alternate translation: "God will always be faithful to his covenant with us" or "God will always faithfully love us" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])
This generalization refers to those who were at the feast in Jerusalem, not necessarily to every person who lived in Israel. (See: [[rc://en/ta/man/jit/figs-hyperbole]])