Reb Aryeh Levine zt'l would frequent the Yerushalayim prisons to visit the Jewish inmates. Once, someone asked a recently released prisoner whether he plans to steal again. He replied that he won't return to the road of crime. And then he added, "Maybe I will steal once. Reb Aryeh Levine doesn't have a watch, and I want to get him one. If I can't get it for him in legal ways, I will steal. But after that, I won't steal again."
The man went to Reb Aryeh and asked him, "What kind of students do you have? I just spoke with one, and he said he would steal to get you a watch."
Reb Aryeh Levine replied, "I don’t tell them mussar, and I don't tell them not to steal. I teach them one thing: They must only speak the truth. And as you saw, this person was very truthful. He admitted that he would steal one more time. If someone is careful never to lie, he won't steal. He knows that if someone asks him whether he stole, he will have to admit the truth, so with being cautious with this one matter, he won't steal, and he won't commit other aveiros, either."
Once, a person was smoking a cigarette on the street on Shabbos, while Reb Aryeh was approaching from the other side. One of Reb Aryeh's ex-prisoner friends ran to hear what Reb Aryeh would tell the smoker. Reb Aryeh said, "I won't tell you to stop smoking, because you know on your own that it is Shabbos, and you smoke, regardless. But I will ask you not to put out the cigarette when you finish smoking it. Let it extinguish on its own. That way, you will have one aveirah less on Shabbos."
A couple of weeks later, this man said (to the person who had listened in on the conversation): "Now, not only don't I smoke on Shabbos, I don’t smoke on the weekdays, either."
