In the earliest documents of the Islamic community, we find that the word sunna (the path, or the example of a tribal leader in seventh-century Arabia) was applied to the new religious leaders – Muhammad, of course, but also the first caliphs (or successors) like Abu Bakr, Umar, Uthman and Ali, and even governors of far-flung provinces. Within a century or so, sunna was used almost exclusively of the Prophet himself; and still later, “the Sunna” referred to the growing…