The third way of preservation of the Sunnah was to bring it into practice.
The knowledge of Sunnah was not merely a theoretical knowledge, nor were the teachings of the Holy Prophet (SAWS) merely philosophical. They related to practical life. The Holy Prophet (SAWS) did not confine himself to giving lessons and sermons only; he also trained his companions practically. Whatever they learnt from the Holy Prophet (SAWS) they spared no effort to bring it into actual practice. Each companion was so enthusiastic in practicing the Sunnah of the Holy Prophet (SAWS), that he tried his best to imitate even his personal habits.
Thus the whole atmosphere was one of following the Sunnah. The Sunnah was not a verbal report only; it was a living practice, a widespread behavior and a current fashion demonstrating itself everywhere in the society, in all the affairs of their daily life.
If a student of mathematics confines himself with remembering the formulas orally, he is likely to forget them after a lapse of time, but if he brings them in practice, ten times a day, he shall never forget them.
Likewise, the Sunnah was not an oral service carried out by the companions. They brought it into their daily practice. The Sunnah was the centre of gravity for all their activities. How could they forget the Sunnah of the Holy Prophet (SAWS) around which they built the structure of their whole lives?
Thus, constant practice in accordance with the dictates of the Sunnah was another major factor which advanced the process of preserving the Sunnah and protected it from the foreign elements aiming at its distortion.