When Hagar, the slave of the Matriarch Sarah whom she had given to the Patriarch Avraham for a wife, fled from her mistress, she had an encounter with three angels who relayed a Heavenly message to her. This is evident from the fact that "an angel of G-d" is mentioned three times in the passages describing this encounter (Bereshet 16:7-11).

Rabbi Shimon bar Yochai sadly reflected on this event when he encountered a demon named Ben Tamalyon on his way to Rome to seek an annulment of some terrible decrees against the observance of important mitzvot. When the demon offered to assist him in his mission, Rabbi Shimon wept that the slave of the Patriarch was privileged to meet three angels while he was not privileged to meet even one.

"Let the miracle come from any source," he exclaimed and accepted the demons offer. The strategy was for the demon to precede Rabbi Shimons arrival in Rome and enter into the body of the Roman emperors daughter. She would subsequently go mad and cry for the help of Rabbi Shimon whose whispered command to the demon would cause him to depart and allow the princess to regain her senses.

The plan worked perfectly and the grateful emperor rewarded the Sage by allowing him to enter the royal vaults and take whatever he wished. Rabbi Shimon thus succeeded in finding the document containing those awful decrees and destroying it.

Maharsha adds a fascinating note to this story. A heretic, he writes, once asked a Torah scholar why it was indeed a demon that had been chosen for saving Jewry from those decrees which threatened the very essence of Judaism. His explanation was that the idea of issuing such anti-religious decrees could only have been planted in the mind of the emperor by a demon, so it was that demon who was given the job of having them annulled.

The term meilah, which serves as the title and principal subject of this mesechta, appears in the Torah chapter describing the sacrifice which one must offer if he involuntarily was guilty of making personal use of property belonging to the Beit Hamikdash (Vayikra 5:15).

Not only does this atonement differ from that required for other involuntary sins in that here the sacrifice is an asham rather than a chatat, but the sin itself is described as meilah rather than just as ordinary sin.

The Sefer Hachinuch writes that the reason for this special term is to indicate that it is a very serious sin to appropriate Heavenly property for personal use.

The gemaras definition of meilah is "change". When one appropriates Beit Hamikdash property for personal use he is changing its status from sacred to secular. The same term is applied to a woman suspected of marital infidelity (Bamidbar 5:12) because adultery is also making a change in regard to the man to whom the woman owes her loyalty. It appears once again in regard to the betrayal of G-d by the tribes of Reuven and Gad and half the tribe of Menashe (Divrei Hayamim I 5:25), a betrayal which represented a change in whom these Jews owed their loyalty to.