Surah 7. Al-A'raf, Ayah 33

The forbidden things are described in four categories: (1) what is shameful or unbecoming; the sort of things which have also legal and social sanctions, not of a local but of a universal kind; they may be called offences against society: (2) sins against self and trespasses or excesses of every sort; these are against truth and reason; here would come in indiscipline, failure in doing intangible duties not clearly defined by law; selfishness or self-aggrandisement, which may be condoned by custom and not punished by law, etc.- (3) erecting fetishes or false gods; this is treason against the true God; and (4) corrupting religion by debasing superstitions, etc.