Albert Barnes on Acts 24:23

And he commanded, etc. It is evident from this verse, that Felix was disposed to show Paul all the favours that were consistent with his safe keeping. He esteemed him to be a persecuted man, and doubtless regarded the charges against him as entirely malicious. What was Felix's motive in this cannot be certainly known. It is not improbable, however, that he detained him,

(1.) to gratify the Jews by keeping him in custody as if he were guilty; and,

(2.) that he hoped the friends of Paul would give him money to release him. Perhaps it was for this purpose that he gave orders that his friends should have free access to him, that thus Paul might be furnished with the means of purchasing his freedom.

(b) "liberty" Acts 27:3, 28:16