《管子·禁藏》
第三，了解放国君主淫乐，就设法消磨他的意志。送给他乐队美人，在内蒙蔽他；送给的诌媚的侍臣和美丽的乘马，在外蒙蔽他。内外蒙蔽，可以促成其国败。
三曰听其淫乐，以广其心，遗以竽瑟美人，以塞其内；遗以谄臣文马，以蔽其外。外内蔽塞，可以成败。
Thirdly, if you know that the emperor of the subjugated country is lustful, find a way to weaken his will. Send him a band of beauties to confuse him from within; send him a group of flattering courtiers and beautiful riding horses to confuse him from without. Internal and external confusion can lead to the defeat of his country.