How did the scholars agree on the purity of water if its three characteristics do not change, even though the Hadith of Umm Hani' about washing Zaynab with water containing camphor indicates a change in the water's color, smell, and taste? So, would the water here be pure but not purifying?

There are two scenarios for placing camphor in water:

The first: That it is placed therein and changes its color, taste, or smell in a way that prevents the designation of it as water. In this case, the water loses its purifying property.

The second: That some camphor is placed therein and causes a slight change that does not prevent the designation of it as water. In this case, the water does not lose its purifying property. This is supported by the Hadith of Umm Atiyyah al-Ansariyyah regarding the washing of Zaynab, the daughter of the Prophet (peace and blessings of Allah be upon him): "Wash her three, five, or more times if you deem it appropriate, with water and sidr, and put camphor or some camphor in the last wash." This view is the most preponderant.