Ali Baba and the Forty Thieves

Ali Baba is a poor woodcutter who secretly watches as 40 thieves hide their booty in a cave, the door to which can be opened only by the verbal command of "Open, Sesame!" He later uses this magic phrase, steals riches from the cave.
The 40 thieves make multiple attempts to capture Ali Baba but they are out-smarted by the servant girl, Morgiana.