Acts 26:25-26

25 But he said, I am not mad, most noble Festus; but speak forth the words of truth and soberness.
26 For the king knoweth of these things, before whom also I speak freely: for I am persuaded that none of these things are hidden from him; for this thing was not done in a corner.

Acts 26:25-26 In-Context

23 That Christ should suffer, and that he should be the first that should rise from the dead, and should shew light unto the people, and to the Gentiles.
24 And as he thus spake for himself, Festus said with a loud voice, Paul, thou art beside thyself; much learning doth make thee mad.
25 But he said, I am not mad, most noble Festus; but speak forth the words of truth and soberness.
26 For the king knoweth of these things, before whom also I speak freely: for I am persuaded that none of these things are hidden from him; for this thing was not done in a corner.
27 King Agrippa, believest thou the prophets? I know that thou believest.
28 Then Agrippa said unto Paul, Almost thou persuadest me to be a Christian.