Acts 23:20,21

‘And he said, “The Jews have agreed to ask you to bring Paul down tomorrow to the council, as though you would enquire somewhat more exactly concerning him. Do not therefore yield to them, for there lie in wait for him of them more than forty men, who have bound themselves under a curse, neither to eat nor to drink till they have slain him, and now are they ready, looking for the promise from you.” '

Then the lad explained what he had overheard. On the next day the Jews would pretend that they wanted to question Paul, but really it was simply a ruse in order to get Paul out of the fortress. Once he left the fortress they would attack the guards and kill him. All they were now waiting for was the chief captain's promise that Paul would be forthcoming. No doubt the chief captain questioned the lad about the source of his information, and was satisfied. He would know that the High Priest Ananias was quite likely to be involved in such a plot. It was typical of his methods.