One such change was that illness was caused by sin. This was because sin caused qi to leave the body. In order to cure any illness, repentance was a crucial factor in ensuring that the loss of qi could be staunched. Repentance could be accomplished by spending time in a 'Chamber of Silence,' and reflecting on one's sins, or by beating one's breasts and kowtowing to heaven. Illness could also be cured in other ways as well, among them using medicinal herbs and by listening to ritual music. Eating very little was also of extreme importance, and an ideal diet would consist of no food at all, but only noncorporeal things such as air, which the person could absorb through meditation.