What is the ruling concerning the water that splashes onto clothes from the tap during istinja'?

The water that touches clothes or the body from a tap is pure. As for water used to wash away impurity, if some of its characteristics change due to the impurity, then it is impure, and whatever it touches must be washed. If it does not change, then it is pure. This is the madhhab of Imam Malik, and one should be wary of the devil's whisperings in this regard. As Shaykh al-Islam Ibn Taymiyyah said: "As for water, it is pure in itself, but if impurity mixes with it and becomes apparent in it: then its use becomes the use of that foul substance. It is forbidden to use it only because of the foul substance that mixed with it, not because it is foul in itself. If there is no apparent indication of the foul substance mixing with it, then this estimation and possibility, despite the water being pure and unchanged, falls under the category of hardship that Allah has negated from our Sharīʿah." The Imams have stipulated that if water falls from a spout or similar source, and there is no indication of impurity, one is not required to inquire about it; in fact, it is disliked to do so. Shaykh Ibn 'Uthaymeen emphasized that the default state of clothes is purity, and they do not need to be washed unless it is certain that they have been touched by something impure.