Albert Barnes on Acts 25:20

And because I doubted of such manner of questions. See the margin. Because I hesitated about the right way of disposing of them; because I was ignorant of their nature and bearing, I proposed to go to Jerusalem, that the matter might be there more fully investigated. It is obvious, that if Paul was not found guilty of any violation of the laws, he should have been at once discharged. Some interpreters understand this as affirming that he was not satisfied about the question of Paul's innocence, or certain whether he ought to be set at liberty or not.

(1) "doubted" "Or, I was doubtful how to inquire hereof"