See Acts 5:33. They were cut to the heart; they were angry to madness. They gnashed on him with their teeth: gnashing of teeth is the curse of the damned, Matthew 8:12, which men by their sins do prepare for. This corrosive was applied by a skilful hand, would they have endured the cure.
Related Commentaries of Acts 7:54
Acts 7:54
54 When they heard these things, they were cut to the heart, and they gnashed on him with their teeth.