During the Tang Dynasty, there lived a celebrated painter named Zhang Zao, who was especially famous for his exquisite landscape and pine tree paintings. What made Zhang Zao's art remarkable was his unique technique: he could hold a brush in each hand and paint simultaneously. With one brush, he would depict the vibrant green pine needles, while with the other, he rendered the rugged, gnarled trunks. His pine trees were so lifelike that all who saw them were amazed, hailing him as a 'divine painter.'

Zhang Zao also possessed two other extraordinary painting skills: he would paint with a brush that had lost its head, and he could also use his fingers. He would take a piece of white silk, dip his fingers in paint, and with a few deft strokes and smudges, he could create a complete landscape scene with trees.

The idiom '双管齐下' (shuāng guǎn qí xià), meaning 'two brushes at once,' originated from this story, later evolving to describe the act of pursuing two different approaches or methods at the same time to achieve a goal.