Seeking the name of a foreign novel

The general content was about a poor teacher who had nothing but a big desk, and his students admired him because of it. His happiest moment was when his students were admitted to a good school or received a reward. He would be invited to the students 'homes and receive everyone's respect. He could also give an impromptu speech and receive everyone's applause. Although he was poor, he was proud to be able to teach and educate people. Once he received an invitation to teach in a rich family. He wore his most decent clothes and walked half the city to save money. When he arrived at the house, the mistress looked him up and down for a while and asked the servant to send him away with the fare. He straightened his back and said: Thank you for your kindness, Madam, but I can go back by myself. On the way back, he ran into trouble. A policeman intervened and asked him what his profession was. He replied firmly,"I'm a teacher." The police followed him home. The house was full of children waiting for him to go to class. The police asked him to show his ID, and he reluctantly handed it to the police. The police completely ignored his pleading eyes and raised the ID to the children." Children, you have been deceived. This person is not a teacher. He is just a worker." He had a desk, the children shouted. The policeman smiled and said,"I have a desk too, but I'm a policeman." After saying that, the policeman glanced at the ashen instructor mockingly and left. After a moment of silence, he said," That's right, children. I've never been to school. I've learned all I know on my own, so I'm not qualified to teach. I..." He lowered his head and heard the sound of children walking out of the classroom. He seemed to have heard the sound of dignity being shattered. That night, he could not sleep at all. He could no longer teach, and no children would be willing to listen to him. He almost lost the courage to live. The next morning he was awakened by a light knock on the door. He got up to open it, and outside were all his students. Good morning, teacher. The children said in unison. Fighting back his tears, the teacher replied in a choked voice, Good morning, children, let us begin.