Is water used for Istinja' (cleansing after urinating or defecating) considered pure if it emerges unchanged by impurity before the spot is purified?

The water separated from the place of Istinja’ (cleaning oneself after relieving nature) before the impurity is cleansed: if it separates while changed by the impurity, it is impure by consensus. But if it separates without being changed and before the impurity is removed, there is a difference of opinion concerning it. Many scholars consider it impure, while the Malikis and those who agree with them deem it pure. It is permissible for a layperson to follow a specific madhhab (school of thought) or to ask trustworthy scholars.