Guide for the Perplexed, by Moses Maimonides, Friedländer tr. [1904], at sacred-texts.com
THE precepts of the third class are identical with those which we have enumerated in Hilkot de‘ot. Their use is evident; they are rules concerning moral conduct by which the social relations of men are regulated. This is sufficiently clear, and I need not dwell long on it. Know that some precepts prescribe certain acts which are considered as arbitrary decrees without any purpose, but are nevertheless the means of acquiring some moral principle. We shall explain every one of them in its proper place. But of all those precepts which are mentioned in Hilkot dew, it is distinctly stated that their object is to inculcate good moral principles.