Acts 7:54

They were cut to the heart. — Literally, were sawn through and through. (See Note on Acts 5:33.) The word describes a keener pang than the “pricked” of Acts 2:37, producing, not repentance, but the frenzy of furious anger.

They gnashed on him with their teeth. — The passage is worth noting as the only example of the literal use of a phrase with which we are so familiar in its figurative application (Matthew 8:12; Matthew 13:42, et al.). Here it clearly expresses brute passion rather than despair. At this point rage and fury — the fury caused by the consciousness that the stern words are true — had become altogether beyond control. They had passed beyond articulate speech into the inarticulate utterances of animal ferocity.