The Hand of Glory is the right hand of a murderer, removed while he is on the gallows and then pickled and dried.
In Red Sky at Morning, Bela Talbot tricked Dean and stole the Hand of Glory from the Sea Pines Maritime Museum. The hand was haunted by a vengeful spirit of the sailor it belonged to. The sailor was hanged for treason on a ship captained by his brother, thus he exacted vengeance on people responsible for the death of family members.
In Lebanon, the owner of a pawn shop visited by the Winchesters shows them a Hand of Glory on display in his back room. After killing the man, the Winchesters take his collection of occult artifacts, including the Hand of Glory.
|“||Dean, the right hand of a hanged man is a serious occult object. It's very powerful. - Sam||”|
The right hand was chosen to be removed from the corpse of the villain, usually a murderer, because it was deemed the hand most likely to have 'done the deed'. However, some renderings of the custom hold that the left hand was removed, with 'left' being associated with the Latin term denoting sinister.
The term 'hand of glory' is derived from the French 'main de gloire', named for the mandrake root (French: mandragore) which was believed to have magical powers. The mandrake plant was believed to grow beneath the gallows from the residuum of hanged men and grew leaves believed to resemble hands. In Saxon lore, mandrake plants were said to glow at night, which perhaps gave rise to the idea that they aided criminals in their pursuits. A variation on this idea was the belief that a candle made from or held by a hand of glory provided light solely to the person holding it while leaving all others in darkness, or made the holder invisible.