Context- A big portion of this last half of the letter Acts is about Paul being imprisoned. Paul’s friends told him not to go to
And surprise, Paul causes an uproar... for what? Speaking the message. It gets so bad that we read in Acts 23:12-
12The next morning the Jews formed a conspiracy and bound themselves with an oath not to eat or drink until they had killed Paul. 13More than forty men were involved in this plot. 14They went to the chief priests and elders and said, "We have taken a solemn oath not to eat anything until we have killed Paul. 15Now then, you and the Sanhedrin petition the commander to bring him before you on the pretext of wanting more accurate information about his case. We are ready to kill him before he gets here."
~Acts 12-15
So 40+ men turn assassin and make a pact to not eat or drink until they have killed the Paul. They will not eat or drink until this man is dead, until the message is stamped out once and for all.