Monks are allowed to hold dust to repel mosquitoes, but it is forbidden to use strokes made of more colorful and precious things, such as "line drawing".
There are many records of bodhisattvas or elders holding sketches in their hands in the classics. For example, when the Buddha came back from the viewpoint that heaven was his mother, Brahma tried to hold the white strokes to serve the Buddha's rights.
In Zen Buddhism, strokes are regarded as solemn instruments, and the abbot or agent holds the strokes in class, which is called "writing". Therefore, blowing dust is a symbol of the sentence.
Dust blowing is also a famous weapon of Taoism.
There are many strange weapons in Wu Tangmen's martial arts, and blowing dust is one of them. As the saying goes, "the dust blown on your hands is not mortal." Blowing dust in the door means blowing away dust, which is what people carry with them when they travel. In the Taoist system, blowing dust is an instrument in the Dojo, and then it is transformed into a weapon by Taoist priests, which belongs to soft weapons and the like.
People are familiar with the old gentleman in Tai Shang, the real man in Tai Yi, and Lv Dongbin among the Eight Immortals, all of which are powerful in sweeping away dust and their immortal spirit arises spontaneously. It has added endless cultural charm to China Taoist historical documents.