12. Hair doth not invalidate your prayer, nor aught from which the spirit hath departed, such as bones and the like. Ye are free to wear the fur of the sable as ye would that of the beaver, the squirrel, and other animals [#9]
In some earlier religious Dispensations, the wearing of the hair of certain animals or having certain other objects on one’s person was held to invalidate one’s prayer. Bahá’u’lláh here confirms the Báb’s pronouncement in the Arabic Bayán that such things do not invalidate one’s prayer.
13. We have commanded you to pray and fast from the beginning of maturity [#10]
Bahá’u’lláh defines the "age of maturity with respect to religious duties" as "fifteen for both men and women" (Q and A 20). For details of the period of fasting, see note 25.
14. He hath exempted from this those who are weak from illness or age [#10]
The exemption of those who are weak due to illness or advanced age from offering the Obligatory Prayers and from fasting is explained in Questions and Answers. Bahá’u’lláh indicates that in "time of ill-health it is not permissible to observe these obligations" (Q and A 93). He defines old age, in this context, as being from seventy (Q and A 74). In answer to a question, Shoghi Effendi has clarified that people who attain the age of seventy are exempt, whether or not they are weak.
Exemption from fasting is also granted to the other specific categories of people listed in the Synopsis and Codification, section IV.B.5. See notes 20, 30 and 31 for additional discussion.