The distinguishing feature of early Mahometan tradition is, that it was
essentially oral. Even if committed to writing, the tradition acquired no new
authority from the record : it must still be transmitted by word of mouth, the
record counting absolutely for nothing. The canons of tradition formed a
distinct science, and had a literature of their own. It was found necessary to
relax the strict Mahometan law of evidence in its application to tradition:
thus, a single credible witness (instead of the legal two) sufficed, if only
the links of oral transmission were otherwise complete. An exception was also
made in favour of epistolary communications, which at a very early period were
admitted as trustworthy without oral attestation; but under all other
circumstances, the test by word of mouth was rigidly insisted upon, as
essential to the validity of each step in the transmission. Thus the possessor
of the notes or memoranda of a Sheikh could make no recognised use of them
unless he was able to say that they had been orally vouched for by the writer
of the manuscript; and indeed the entire rehearsal of each tradition by the
person transmitting and the person receiving it, in the hearing of each other,
was insisted upon as an indispensable condition of trustworthiness.