By subtlety - By guile, deceit, or in some secret manner, so that the people would not know it.
Jesus was regarded by the people as a distinguished prophet, and by most of them, probably, as the Messiah; and the Sanhedrin did not dare to take him away openly, lest the people should rise and rescue him. They were probably aware that he had gone out to Bethany, or to some place adjacent to the city; and as he passed his nights there and not in the city, there was need of guile to ascertain the place to which he had retired, and to take him.

And consulted that they might take Jesus by subtilty - The providence of God frustrated their artful machinations; and that event which they wished to conduct with the greatest privacy and silence was transacted with all possible celebrity, amidst the thousands who resorted to Jerusalem, at this season, for the keeping of the passover. It was, doubtless, of the very first importance that the crucifixion of Christ, which was preparatory to the most essential achievement of Christianity, viz. his resurrection from the grave, should be exhibited before many witnesses, and in the most open manner, that infidelity might not attempt, in future, to invalidate the evidences of the Christian religion, by alleging that these things were done in a corner. See Wakefield in loco.

And consulted that they might take Jesus by subtlety,.... The Jews had often attempted his life, but he escaped out of their hands; they had sent officers to apprehend him, but to no purpose; they therefore meet and consult together, to form some scheme, and make use of some stratagem, that they might lay hold on him, and keep him; they were for doing this in the most private manner they could:
and kill him; not with their own hands, nor privately; but their scheme was to apprehend him privately, by some secret artifice, and then deliver him to the Roman governor; to put him to death according to law, publicly, for crimes they had to charge him with; hereby Psalm 2:2, had its accomplishment, at least in part.

Take Jesus by subtilty. They were afraid of the people and wished to seize Jesus secretly and deliver him to the Romans to be crucified before the people knew of their designs. See Luke 21:38.