August 7

Whichever obligatory prayer is chosen to be used should be followed in full. If one cannot perform the postures necessary in connection with the long obligatory prayer, he may choose another if ill, or just the very short one. 
- Shoghi Effendi  (From a letter dated 12 July 1955 written on behalf of Shoghi Effendi to an individual believer; included in a compilation: ‘Exemption from Obligatory Prayer’, prepared by the Research Department of the Universal House of Justice)