Stephen had called them out on their hypocrisy and they were cut to the heart. My margin says they were furious. They became as ravenous wolves, gnashing at him with their teeth. The King James version renders this scripture, "They gnashed on him with their teeth." Were they so furious at the hearing of the truth that they literally bit him? Truth being the key word here, for there was no blasphemy and they judged wrongly, killing an innocent servant of God. They did not want to hear the truth. They were comfortable with their position in the synagogue, and this young punk was dangerous and he had to be silenced. "Who does he think he is anyway? And where does he get his education?"