en_tn/act/26/22.md

to the common people and to the great ones about nothing

Here "common people" and "great ones" are used together to mean "all people." Alternate translation: "to all people, whether common or great, about nothing" (See: rc://en/ta/man/translate/figs-merism)

about nothing more than what

This can be stated in positive form. Alternate translation: "about the exact thing that"

what the prophets

Paul is referring to the collective writings of the Old Testament prophets.