The Leshon Hakodesh, otherwise known as the Holy Tongue is the language which the Book of Breathings is written in. Amren is able to read this language after decoding it. This tongue is believed to be written by a species of mighty beings who feared The Cauldron's power and so the Book of Breathings was made to combat it.
- The Leshon Hakodesh (לשון הקודש) is a Jewish term and appellation attributed to the Hebrew language, or sometimes to a mix of Hebrew and Aramaic, in which its religious texts and prayers were written, and served, during the Medieval Hebrew era, for religious purposes. 
- A Court of Mist and Fury (First appearance)