Albert Barnes Commentary Acts 23:14

"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." — Acts 23:14 (ASV)

And they came, and so on. Probably by a deputation.

To the chief priests and elders. The members of the great council, or Sanhedrin. It is probable that the application was made to the party of the Sadducees, as the Pharisees had shown their determination to defend Paul. They would have had no prospect of success had they attacked the castle; and they therefore devised this ingenious mode of obtaining access to Paul, where they might easily dispatch him.

Under a great curse. Greek, "We have anathematized ourselves with an anathema." We have made the vow as solemn as possible.