What is the ruling on purifying impurities in regular and automatic washing machines? And do submersion and wringing purify? And how can the removal of impurity be ensured while a trace of color remains? And what is the meaning of thorough washing and a single wash for a child's urine?

To get rid of waswas (obsessive whisperings) concerning purity, one can adopt the view of Malik and Ibn Taymiyyah that water does not become impure unless its characteristics change. Automatic washing machines purify clothes if the impurity itself is removed or if the impurity is only a ruling (i.e., not a visible substance); this is because the water flows over the impurity. The default ruling for something doubtful is purity. Immersing an impure garment in water is not sufficient unless water is poured over it until the impurity itself is removed. It is sufficient for water to reach the inner part of the impurity. Thorough washing removes the impurity itself (its color, smell, or taste), or it is the flowing of water over a ruling impurity, and wringing is not a condition. Water separated from the impurity before its purification is impure, or its description should be considered: if it has changed, then it is impure; otherwise, it is pure. The color of an impurity that is difficult to remove is excused. For purifying urine, it is sufficient for water to flow over the impure spot, and wringing, rubbing, or a specific number of washes are not conditions.