An old man lived alone. He was once a tailor but now too old to work. His hands shook, and his eyes were weak.

He had three sons who were busy with their own lives. They visited him only for dinner once a month. The old man worried that his sons might forget him.

He thought of a plan. He asked friends for help. A carpenter made him a big chest. A locksmith gave him an old lock. A glassblower gave him broken glass. The old man filled the chest with glass and locked it. He put it under his table.

When his sons came, they noticed the chest. They thought it was filled with treasure. They wanted to protect the treasure, so they took turns to live with and care for the old man. The sons cooked for the old man, washed his laundry and accompanied him on long walks. This continued until the old man passed away.

After his funeral, the sons opened the chest. They found only broken glass. They realized their father had taught them a lesson. They had ignored their duty to him. 

The story teaches responsibility. Children can learn from this by helping their family and showing care every day. It's important to be kind and attentive without expecting a reward.