Charles Ellicott Commentary Matthew 26:4

"and they took counsel together that they might take Jesus by subtlety, and kill him." — Matthew 26:4 (ASV)

That they might take Jesus by deceit — The plan implied in these words and in the phrase that follows, “not on the feast day,” seems to have been hastened by the unexpected treachery of Judas.

They had intended to wait until the feast was over, but the temptation this offered was too great to resist. As a result, they went beyond the limits their own caution had suggested, becoming willing to risk an “uproar among the people” during the Paschal Feast.