Judges 9:52

Went hard unto the door. — Hard, i.e., close. Like other bad men, Abimelech was not lacking in physical courage. He had all his father’s impetuous energy. The peril of such rashness served the Israelites as a perpetual warning (2 Samuel 11:21).

To burn it with fire. — He naturally anticipated another hideous success like that at Millo.