Is the water that comes out of the penis after washing it—after urinating while standing—pure or impure, knowing that it often gets on clothes?

It is preferable to urinate while sitting, but it is permissible to do so while standing if one is certain that clothes and body will not be contaminated with impurity, and that the 'awrah (private parts) will not be exposed. It has been authentically reported that the Prophet (peace and blessings be upon him) urinated while standing to show its permissibility or due to necessity. As for the water that drips during istinja' (washing after defecation or urination), it is impure unless the impurity has been removed, and one must be careful not to let it touch clothes. It is preferable to use tissues or similar items for istijmar (cleaning with solid objects) to remove the impurity, then wash the area with water if there is a concern of soiling clothes.