In a monastery of the Order of Citeaux...lived two young Religious, named Gertrude and her sister Margaret. The former, although otherwise virtuous, did not sufficiently watch over her tongue; she frequently allowed herself to transgress the rule of silence prescribed, some times even in choir, before and after the chanting of the Office. Instead of recollecting herself with the reverence due to that holy place, she addressed useless words to her sister, who was placed next to her, so that, besides her violation of the rule of silence and her lack of piety, she was a subject of disedification to her companion. She died whilst still young, and a very short time after her death, Sister Margaret, on going to Office, saw her come and place herself in the same stall she had occupied whilst living.
At this sight the sister was almost about to faint. When she had sufficiently recovered from her astonishment, she went and told the Superior what she had just seen. The Superior told her not to be troubled, but, should the d ceased appear again, to ask her, in the name of God, why she came.
She reappeared the next day in the same way, and, according to the order of the Prioress, Margaret said to her, " My dear Sister Gertrude, whence do you come, and what do you want?" "I come," she said, "to satisfy the Justice of God in this place where I have sinned. It was here, in this holy sanctuary, that I offended God by words, both useless and contrary to religious respect, by disedification to all, and by the scandal which I have given to you in particular. Oh, if you knew," she added, "what I suffer ! I am devoured by flames, my tongue especially is dreadfully tormented." She then disappeared, after having asked for prayers.
~ Excerpt from Purgatory: Illustrated by the Lives and Legends of the Saints by Fr. F.X. Schouppe, S.J.