The Kitáb-i-Aqdas - The Most Holy Book
Index term: for shrouds, under Silk
k130.
The Lord hath decreed, moreover, that the deceased should be enfolded in five sheets of silk or cotton. For those whose means are limited a single sheet of either fabric will suffice. Thus hath it been ordained by Him Who is the All-Knowing, the All-Informed. It is forbidden you to transport the body of the deceased a greater distance than one hour's journey from the city; rather should it be interred, with radiance and serenity, in a nearby place.
n149.
The Lord hath decreed that the dead should be interred in coffins
In the Bayán, the Báb prescribed that the deceased should be interred in a coffin made of crystal or polished stone. Shoghi Effendi, in a letter written on his behalf, explained that the significance of this provision was to show respect for the human body which "was once exalted by the immortal soul of man".
In brief, the Bahá'í law for the burial of the dead states that it is forbidden to carry the body for more than one hour's journey from the place of death; that the body should be wrapped in a shroud of silk or cotton, and on its finger should be placed a ring bearing the inscription "I came forth from God, and return unto Him, detached from all save Him, holding fast to His Name, the Merciful, the Compassionate"; and that the coffin should be of crystal, stone or hard fine wood. A specific Prayer for the Dead (see note 10) is ordained, to be said before interment. As affirmed by 'Abdu'l-Bahá and the Guardian, this law precludes cremation of the dead. The formal prayer and the ring are meant to be used for those who have attained the age of maturity, i.e. 15 years of age (Q&A 70).
With regard to the material from which the coffin is to be made, the spirit of the law is that coffins should be of as durable a material as possible. Hence, the Universal House of Justice has explained that, in addition to the materials specified in the Aqdas, there is no objection to using the hardest wood available or concrete for the casket. For the present, the Bahá'ís are left free to make their own choices in this matter.
n151.
the deceased should be enfolded in five sheets of silk or cotton
In the Bayán, the Báb specified that the body of the deceased should be wrapped in five sheets of silk or cotton. Bahá'u'lláh confirmed this provision and added the stipulation that for "those whose means are limited a single sheet of either fabric will suffice".
When asked whether the "five sheets" mentioned in the law referred to "five full-length shrouds" or "five cloths which were hitherto customarily used", Bahá'u'lláh responded that the intention is the "use of five cloths" (Q&A 56).
Concerning the way in which the body should be wrapped, there is nothing in the Bahá'í Writings to define how the wrapping of the body is to be done, either when "five cloths" are used or only "a single sheet". At present, the Bahá'ís are free to use their judgement in the matter.