Does the transfer of water between the limbs during ablution (Wudu') and ritual bathing (Ghusl) (such as the transfer of water from the face to the hands during rubbing, or from the chest to the abdomen and thighs during Ghusl) necessitate it becoming Musta'mal (used) water, and is the issue of Musta'mal water and scooping limited to the Shafi'i school of thought?

The water that falls from the top of the body to its bottom during ablution (wudu) or ritual bath (ghusl) is not considered musta'mal (used water), because the body of the person performing ablution or ghusl is like a single limb, and water does not become musta'mal until it separates from the limb. The Hanbalis, Shafi'is, and Hanafis have explicitly stated this. The Malikis are of the view that musta'mal water is sufficient for purification as long as it has not changed. As for the intention of scooping water from a vessel that contains less than two qullahs, the Shafi'is differentiate in this matter, while the majority (of scholars) hold that scooping does not affect the water.