This question is used to either inform or remind the readers that the information about Nadab is in this other book. See how you translated a similar phrase concerning Judah in [1 Kings 14:29](../14/29.md). This rhetorical question can be written as a statement. Alternate translation: "they are written in the book of the events of the kings of Israel." (See: [[rc://en/ta/man/jit/figs-rquestion]])
This can be stated in active form. Alternate translation: "someone has written about this in the book of the events of the kings of Israel." (See: [[rc://en/ta/man/jit/figs-activepassive]])