Acts 23:21 (KJV)

Then the chief captain took him by the hand, and went with him aside privately, and asked him, What is that thou hast to tell me?

And he said, The Jews have agreed to desire thee that thou wouldest bring down Paul to morrow into the council, as though they would enquire somewhat of him more perfectly.

But do not thou yield unto them: for there lie in wait for him of them more than forty men, which have bound themselves with an oath, that they will neither eat nor drink till they have killed him: and now are they ready, looking for a promise from thee.

So the chief captain then let the young man depart, and charged him, See thou tell no man that thou hast shewed these things to me.

And he called unto him two centurions, saying, Make ready two hundred soldiers to go to Cesarea, and horsemen threescore and ten, and spearmen two hundred, at the third hour of the night;