Samu(作務,samu?) refers to physical work that is done with mindfulness as a simple, practical and spiritual practice. Samu might include activities such as cleaning, cooking, gardening, or chopping wood. Samu is a way to bring mindfulness into everyday life as well as to get things done. Samu is popular in Zen monasteries, particularly as a means of maintaining the monastery and as practicing mindfulness.
If you consider quietude right and activity wrong, then this is seeking the real aspect by destroying the worldly aspect, seeking nirvana, the peace of extinction, apart from birth and death. When you like quiet and hate activity, this is the time to apply effort. Suddenly when in the midst of activity, you topple the sense of quietude-that power surpasses quietistic meditation [seated meditation] by a million billion times.
Mindfulness means accepting reality just as it is. Samu is a means of finding Buddha-nature in everyday life, that reality has ever been pure from the very beginning, which was the central idea behind a Japanese movement called "primordial enlightenment".