Cantiga 67 of the Cantigas de Santa Maria of Alfonso X

A generous nobleman devoted much of his money to charity. He established a hospital where the poor could eat and sleep. He hired young men to serve the needy.		The devil entered the body of a handsome young man and offered his services to the nobleman. He was hired as a squire and fulfilled all of his duties.
The devil in the guise of a squire sought to harm his master. He encouraged him to go hunting and fishing so that he might be killed.		Every morning, the nobleman prayed to the Virgin; consequently, the devil was unable to kill him.
One day a bishop visited the nobleman. The devil in the guise of a squire was afraid to meet him and feigned illness. The bishop insisted on seeing the squire and demanded that he relate what he had done.		The devil said that he had entered a dead man’s body in order to deceive his master. He explained that he would have killed his master, if the Virgin had not protected him. Then the devil shed the dead man’s body and disappeared.