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Moreover, medicines of the body are effective in producing health through
some property in them which the intellectuals do not apprehend with their
intellect, but in respect to which one must accept the statement of the
doctors; and these in turn are dependent on the prophets who by
prophethood have grasped the properties of things. Similarly I came of
necessity to realize that in the case of the medicines of formal worship,
which have been fixed and determined by the prophets, the manner of their
effectiveness is not apprehended by the intellectual explanations of the
intellectuals; one must rather accept the statements (taqlid) of the prophets
who apprehended those properties by the light of prophecy, not by
intellectual explanation.

Again, medicines are composed of ingredients differing in kind and
quantity, one, for instance, is twice another in weight and amount; and this
quantitative difference involves secret lore of the same type as knowledge
of the properties. Similarly, formal worship, which is the medicine for the
disease of the hearts is compounded of acts differing in kind and amount;
the prostration (sujud) is the double of the bowing (ruku’) in amount, and the