This idiom comes from Zhuangzi's Happy Travel.
There is a kind of fish named Kun in the north. Kun is so big, I don't know its thousands of miles; Become a bird. Its name is Peng. Peng's back is thousands of miles away; Fly away angrily, its wings hang in the sky like clouds. If it is a bird, shipping will migrate to Nanming. South ghost, Tianchi also.
"Qi Xie", ambition is strange. The text of "Hehe" says: "Peng moved to Nanming, and the water hit three thousand miles. It was Jiu Wan Li who climbed up and went to rest in June. " Wild horses, dust and creatures are blowing with interest. The sky is gray, and its positive color is evil? Far away and everything is extremely evil? It looks down. If it is, it's gone.
Translation:
There is a kind of fish in the North Sea. Its name is Kun. Kunming is very big. I don't know how many miles it is. Kun becomes a bird, and its name is Peng. Peng Bei is thousands of miles long; When it vibrates its wings and flies directly, its wings are like clouds hanging on the horizon. This bird will migrate to the South China Sea when the wind blows the sea. The sea in the south is a huge natural pool.
Qi Xie is a book that records some strange things. It is recorded in the book: "When Peng moved to the South China Sea, flapping his wings on the water surface could stir up waves of 3,000 miles, fly around the whirlwind to the high altitude of Wan Li, and leave the North Sea by the June wind." Swimming like wild horses, flying dust and animals are all moved by the wind. The sky is boundless, is it its original color? Is it boundless? When Peng looked down, he actually saw the same thing.