John Calvin on John 18:8

8. I have told you that it is I. Here we see how the Son of God not only submits to death of his own accord, that by his obedience he may blot out our transgressions, but also how he discharges the office of a good Shepherd in protecting his flock. He sees the attack of the wolves, and does not wait till they come to the sheep which have been committed to his care, but immediately goes forward to guard them. Whenever, therefore, either wicked men or devils make an attack upon us, let us not doubt that this good Shepherd is ready “Que ce bon Pasteur ne soit prest.” to aid us in the same manner. Yet by his example Christ has laid down to shepherds a rule which they ought to follow, if they wish to discharge their office in a right manner.