He (the Guardian) does not feel that the friends should make
a practice of saying grace or of teaching it to children. This is not
part of the Bahá’í Faith, but a Christian practice, and as the Cause
embraces members of all religions we should be careful not to
introduce into it the customs of our previous beliefs. Bahá’u’lláh
has given us the obligatory prayers, also prayers before sleeping,
for travellers, etc., we should not introduce a new set of prayers
He has not specified, when He has given us already so many for
so many occasions….