Scientists have unanimously agreed that all water is pure in itself and purifies anything else, except sea water, for which there is disagreement. Likewise, they also agreed that what changes water is something that is often inviolable. It does not take away its quality of purification, except for pure water. Ibn Sirin disagreed about it and the one I went to. Everything that is called water in general is pure and purified, whether it is sea water or tanks. They also agreed that water in which impurity has changed its color, taste, smell, or all of these descriptions is not permissible for purification. If the water has not changed and not one of its characteristics remains as it was originally. Of purity and purification, and it did not affect the impurity that occurred in it, except that I know in this issue a disagreement regarding a little water in which a little impurity occurs, such that nothing of its characteristics is changed.