Is it permissible to wash the hands with water and soap when performing major ablution (ghusl), after washing the private parts (qubul and dubur)?

There is no requirement to wash one's hands with soap before performing Wudu (ablution) or Ghusl (ritual bath). However, if one does so, it is permissible, provided that the soap does not alter the water used for Wudu or Ghusl. If the water is altered by it, then it is not suitable for purification according to some jurists. However, if Wudu is performed from a tap or similar source, and the water is altered by what was already on the limb, this does not invalidate the purity. It is preferable to remove any soap residue from the hands before beginning Wudu or Ghusl.