[This is the real reason people call Law the Surgeon of Death. He'll save people's lives with his skill and power, then immediately torture them with his atrocious bedside manner.]

You're gonna repeat it back to me one more time after dinner. I won't let you leave until I know you've got it down. These are the very basics, you know.

[He can't make sure Law will follow through, but he can make sure that he memorizes this shit. At the very least, this way, the guy shouldn't make the same mistake twice.]