Books of Djehuti is a text used in the trial of Ra . The text contains knowledge about Ra's true history and language, along with the password and address of the Stargate -via an implant. When the trial ends, the participant must choose whether to retain the knowledge of Breed history or his language.
In 1999, when SG-1 was forced to attend the trial of Ra and during the test with books by Djehuti took Teal'c knowledge from the book in the belief that it can be dangerous for Daniel Jackson to accept the knowledge, his symbiote was performed stationary until the implant was away. (SG1: "The Barque of Heaven")