Acts 23:13

"And when it was day, certain of the Jews banded together, and bound themselves under a curse, saying that they would neither eat nor drink till they had killed Paul. And they were more than forty which had made this conspiracy." "They bound themselves under a curse," it says. See how vehement and revengeful they are in their malice! What means, "bound under a curse?" Why then those men are accused forever, seeing they did not kill Paul. And forty together. For such is the nature of that nation: when there needs concerting together for a good object, not even two concur with each other: but when it is for an evil object, the entire people does it.

"We have bound ourselves," they say, "under a curse, that we will not eat nor drink." What is all this zeal? "Bound themselves by a curse:" it was a kind of necessity that those men fastened on themselves by the curse. "That they would neither eat nor drink." Behold fasting the mother of murder! Just as Herod imposed on himself that necessity by his oath, so also do these. For such are the devil's ways: under the pretext forsooth of piety he sets his traps.