Lady Aisha (may Allah be pleased with her) narrates: Staying in the valley of Muhassab is not a Sunnah. The Messenger of Allah (peace be upon him) stayed in this valley only because it was a convenient place for his departure. Imam Abu Bakr (may Allah have mercy on him) says that Lady Aisha (may Allah be pleased with her) said that staying in the valley of Muhassab is not a Sunnah. By this, she meant that it is not an act that people are obligated to follow. Because all the actions of the Prophet (peace be upon him), even if they are permissible, are referred to as Sunnah. But people can follow this Sunnah because it is permissible, however, this act is not obligatory upon them. (That is, the one who does not do this act will not be sinful nor will any expiation become obligatory upon him.)