Like I tell my kids “Don’t be talking when you should be shooting.” I’m guessing that’s a Dirty Harry line or something.
[Tuco is in a bubble bath. The One Armed Man enters the room]
One Armed Man: I've been looking for you for 8 months. Whenever I should have had a gun in my right hand, I thought of you. Now I find you in exactly the position that suits me. I had lots of time to learn to shoot with my left.
[Tuco kills him with the gun he has hidden in the foam]
Tuco: When you have to shoot, shoot. Don't talk.