It wouldn’t be the first time his sharp tongue had cut his own throat.

He whom the flame of jealousy encompasses, will at last, like the scorpion, turn the poisoned sting against himself.

If I ever marry, it will be on a sudden impulse - as a man shoots himself.

The blade itself incites to deeds of violence.

A man who wants to mutilate himself is certainly damned, isn't he?

108. A Fool’s Tongue is long enough to cut his own Throat.

This is my knife. It is very sharp and very eager to hurt you.

With sharp things, always cut away from yourself.

1657. Give him but Rope enough, and he'll hang himself.

For such a patient it would probably be a complete non sequitur to attempt to kill his self, by cutting his throat, since his self and his throat may be felt to bear only a tenuous and remote relationship to each other, sufficiently remote for what happens to the one to have little bearing on the other.

I'll beat him so bad he'll need a shoehorn to put his hat on.

"It'll be your own torture," he said, serious. "I hope to God it'll torture you to madness."

Never try to reason with a man who can see the blade swinging for his head.

If I ever meet myself,' said Zaphod, 'I'll hit myself so hard I won't know what's hit me.