January 3

With reference to your question regarding the three daily obligatory prayers: the Bahá'í worshipper is not required to recite them all each day, but has to choose one, and should also strictly conform to any instructions revealed by Bahá'u'lláh in connection with its recital, such as the raising of hands, various genuflexions, etc. Those who for some reason or other, especially when physically unable to observe these regulations owing to illness or some bodily defect, cannot conform to these instructions, should preferably choose the short prayer, which is exceedingly simple. 
- Shoghi Effendi  (From a letter dated 7 December 1939 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)