The Universal House of Justice has received your email letter dated 9 March 2011 asking whether saying one’s obligatory prayers when one is ill is considered an act of disobedience. It is understood that the provision in Question and Answer 93 of The Kitáb-i-Aqdas: The Most Holy Book which concerns you is the following:
In truth, I say that obligatory prayer and fasting occupy an exalted station in the sight of God. It is, however, in a state of health that their virtue can be realized. In time of ill health it is not permissible to observe these obligations; such hath been the bidding of the Lord, exalted be His glory, at all times. Blessed be such men and women as pay heed, and observe His precepts. All praise be unto God, He who hath sent down the verses and is the Revealer of undoubted proofs!
You may be sure that there is no reason for you to be distressed. Bahá’u’lláh has clarified that He has granted exemptions from fasting and obligatory prayer to those who are weak from illness or old age. Not having been aware of this exemption, you carried out what you understood to be your Bahá’í obligation. Now that you are cognizant of this aspect of Bahá’í law, you will be able to observe it with this knowledge, bearing in mind that ultimately decisions pertaining to exemptions are a matter of conscience and are left to the individual’s discernment, as explained in note 20 in The Kitáb-i-Aqdas.
The Universal House of Justice has clarified that the provisions in the Kitáb-i-Aqdas granting exemptions from certain duties and responsibilities are, as the word indicates, exemptions and not prohibitions. Any believer is, therefore, free to avail himself or herself of an applicable exemption if he or she so wishes. However, the House of Justice counsels that, in deciding whether to do so or not, the believer should use wisdom and realize that Bahá’u’lláh has granted these exemptions for good reason.
(Universal House of Justice to an individual, 9 May, 2011)