These are the names of some of the tribes that lived in the northern part of Israel. See how you translated "Zebulun" in [2 Chronicles 30:10](../30/10.md). (See: [[rc://en/ta/man/jit/translate-names]])
To do something "against" instructions means to do something that is not in obedience to the instructions. If needed, the instructions can be stated clearly. Alternate translation: "even though the written instructions said that they must purify themselves first" (See: [[rc://en/ta/man/jit/figs-explicit]])
The word "good" here is a reminder to the people that Yahweh is kind. Alternate translation: "Yahweh, who is good" (See: [[rc://en/ta/man/jit/figs-distinguish]])