7 “But the Jews cried out, saying, If you let this man go, you are not Cæsar's friend: whosoever makes himself a king, speaks against Cæsar.” They thought to inspire Pilate with greater fear by terrifying him about Cæsar, in order that he might put Christ to death, than formerly when they said, “We have the law, and by the law he ought to die, because he made himself the Son of God.” It was not their law, indeed, that impelled him through fear to the deed of murder, but rather it was his fear of the Son of God that held him back from the crime. But now he could not set Cæsar, who was the author of his own power, at nought, in the same way as the law of another nation.
Source: Tractates on the Gospel of John (New Advent)