"For much of Islamic history, the unit through which the Sunna was preserved, transmitted, and understood has been the hadīth (Arabic plural, ahādīth), or a report describing the words, actions, or habits of the Prophet. Unlike the Quran, the hadiths were not quickly and concisely compiled during and immediately after Muhammad’s life. Because hadiths were recorded and transmitted over a period of decades and even centuries, they are not in and of themselves contemporary historical documentation of what Muhammad said and did."