en_tn/2ki/20/15.md

They have seen everything in my house. There is nothing among my valuable things that I have not shown them

Hezekiah repeats the same idea in two ways to emphasize his point. (See: rc://en/ta/man/translate/figs-hyperbole and rc://en/ta/man/translate/figs-parallelism)

There is nothing among my valuable things that I have not shown them

"Nothing" and "not" cancel each other out to make the idea positive. This exaggeration is used for emphasis. Alternate translation: "I showed them absolutely every one of my valuable things" (See: rc://en/ta/man/translate/figs-doublenegatives)