A few examples will illustrate the origin and growth of tradition. Mughîra
  laid claim to a certain property on the strength of an utterance attributed to
  Mahomet. The Caliph, Abu Bekr, refused to admit the claim until the statement
  was corroborated by witness; Ibn Maslama testified that he had heard the
  Prophet affirm the claim, whereupon the Caliph gave judgment in Mughîra's
  favour. Again, during Mahomet's lifetime, Sobaya lost her first husband, and,
  shortly after, began to deck herself out in a manner which plainly implied
  that she already entertained thoughts of attracting a second. A discreet and
  pious Moslem, scandalised at her conduct, told her that she should tarry four
  months before thinking of another marriage; but she, regarding this
  unreasonable, repaired to Mahomet, who confirmed the precept. When, after the
  Prophet's death, people began to gather up his sayings, a certain collector of
  tradition wrote to a friend to visit Sobaya, and record from her own lips an
  exact account of her interview and of the Prophet's precept; and hence the Sunna
  regarding it. On one occasion, Muâvia, while 'engaged in the Syrian campaign,
  referred a doubtful point connected with the rules of warfare to Aly, as the
  person most conversant with the views of Mahomet. So likewise, the son of
  Abbâs, a renowned traditionist, was consulted on the question whether women
  and slaves accompanying the army were entitled to share in the booty; his
  decision, based on the analogy of the Prophet's practice, was that as women
  and slaves used to be present for the care of the wounded,