Acts 23:14,15

‘And they came to the chief priests and the elders, and said, “We have bound ourselves under a great curse, to taste nothing until we have killed Paul. Now therefore do you, with the council, signify to the chief captain that he bring him down to you, as though you would judge of his case more exactly, and we, before he comes near, are ready to slay him.” '

All they needed now was the opportunity. So they went to the chief priests and elders (they avoided the Pharisees) and informed them of their plans. They pointed out that they had put themselves under a curse not to taste anything until Paul was dead. Would the council now ask that Paul be brought before them as before so as to get him out of the fortress. Then as soon as he was out they would attack the guards, fall on him and slay him. The Romans would not be anticipating any such attack in the short journey between the fortress and the Sanhedrin's meeting place by the Temple. And to the disgrace of the Sanhedrin it agreed.