The Snake of the Festival labored on this spell during the time he was trapped within the Rift Between Both Worlds, persistently forwarding it to Hecate. During later events, when the Flame Haze Margery Daw, and Sale Habichtsburg analyze the Psalm they find that the insignia for it holds about 82 different Unrestricted Spells, and Gizo remarks that it would have taken decades to analyze it without a certain "secret item" given to Wilhelmina Carmel by Lamies.
By the request from Bal Masqué, Dantalion had been in charge of deciphering of the Psalm. However he once took arbitrarily some (at least two) old part of the Psalm out, modified it needlessly for his experiments, soon afterward lost interest and unceremoniously parted with it. One of the stolen Psalm was eventually passed into Asiz's hands, becoming the keystone of his "Grand Scheme".
- The Psalm of the Grand Order was first revealed in the eighth light novel volume and named in the tenth. It was not featured in the first season of the anime.