A young man rented a house. The landlord was Grandma Li, who lived alone, and he had almost been living there for 2 years.

After work, the landlord found him and said, “I’m over 80 years old. Since I can tell you’re a reliable, honest kid, from now on, it doesn’t matter whether you pay rent or not. Would you be willing to do me a small favor?”

The young man quickly said, “Please go ahead and tell me what it is. As long as I’m able to do it.”

The old lady said, “Please knock on my door every day when you go to work, …”