Actually, he doesn't even need to say anything. The feds told a court that mere possession after presidency leads to the presumption records are designated personal. Of course, that was for Bill Clinton (who kept tapes of conversations with foreign leaders in his sock drawer)!
en.wikipedia.org/wiki/Church_Co… in 1975 that investigated abuses by the Central Intelligence Agency (CIA), National Security Agency (NSA), Federal Bureau of Investigation (FBI), and the Internal Revenue Service (IRS). Chaired by Idaho Senator Frank Church (D-ID)