Magic Pen Ma Liang wants to buy a pen. He kept it for a long time, but what happened to the pen in Bizhuang?

Ma Liang saved money to buy a pen for the following reasons:

Ma Liang is a figure in myths and legends. According to legend, Ma Liang has a magic pen in his hand, which can turn stone into gold. In this way, Ma Liang helped many poor people in his life. At the beginning of the story, Ma Liang saved money to buy a pen, but he didn't buy it. This is because Ma Liang is a very kind child. On the way to save money for a pen, I met an old woman who was in urgent need of money to save her life. Good Ma Liang donated money to the old woman, so she didn't buy a pen.