- The Koran
- The Sunnah, or the customs, everyday habits and religious practices of the Prophet Muhammad as recorded by his companions and family.
- The Hadith, or Ahadith, the recorded actions and teachings of the Prophet not found in the Koran).
- The ijma, or “universal agreement” within the Muslim community that defines what the Koran and the Sunnah mean, although the principle of ijma has come to mean both an opposition to traditional authority and a principle of toleration.
It is the principle and source least applied, if applied at all, in modern Islam’s derivation of Sharia, which tends to be repressive, discriminatory (especially of women) and unforgiving of miscreants and lawbreakers. In journalist Fareed Zakaria's summation, Sharia means "no music, no liquor, no smoking, no female emancipation."
Sharia was codified in the 8th and 9th centuries. The term originally meant “the path to the watering hole,” meaning the path to God.