Water And Its Kinds

It is written in Durr-ul-mukhtar, and also in Radd-ulmukhtar, which is an explanation of the former:

A minor ablution [an ablution for salat] and a major ablution [ghusl [1]] require using mutlaq water. In other words, mutlaq water is both clean and a cleaner. Mutlaq water is water that takes no other word besides its name and which is solely called water. Water from rain, brooks, streams, springs, wells, seas, and snow is mutlaq water. Najs water [2], flower essence, grape juice and the like, which are mentioned together with their kinds and properties, are not mutlaq water. These cannot be used for making an ablution or ghusl. They are called Muqayyad water. Zamzam water ( a famous well very near the Kaaba in Mecca) can be used for an ablution or a ghusl. It is not even mekruh [3]. It is permissible also to use water that has stayed for some time under the sun. But is tanzihi mekruh [4].

Water issuing and dropping from trees, grass, fruit or from any climbing plant is clean. But an ablution or ghusl is not permissible with it or with any juice extracted from these plants. When something clean is mixed with mutlaq water, if the amount of the substance mixed with the water is more than the water, the water becomes muqayyad. The substance mixed with water may become the greater part in four ways.

Firstly, something solid, such as a sponge or grass, absorbs the water completely.

Secondly, something which is not used in cleaning like soap is heated in the water. Meat broth and bean juice are of this sort. In this case the water becomes muqayyad water even if its three properties did not change and even if it did not lose its fluidity. Water heated with some cleaner such as soap becomes muqayyad if it loses its fluidity.

Thirdly, a solid substance gets mixed with cold water. If the substance changes the name of the water after it is mixed with it, the water becomes muqayyad even if it is not viscous.

The fourth possibility is when a liquid substance gets mixed with water. When a clean substance in liquid form flows into a small pool, if all three properties of the substance are unlike those of water and if two properties of the mixture have changed, it becomes muqayyad. If only one has changed, it does not become muqayyad. Water mixed with vinegar is an example of this type. Milky water is an example of this type because being odorless is common in both of them. And so is water mixed with melon juice because, being colourless and odorless is common in both of them.

[1] ghusl: ablution of the whole body as defined in fiqh.
[2] najs: religiously impure thing.
[3] makruh: (act, thing) improper, disliked and abstained by the Prophet ('alaihi 's-salam); makruh tahrima: prohibited with much stress.
[4] makruh-tanzihi: An act that has been declared to be close to halâl (permissible), or an act that is better not to do it than to do it. Instance: Omitting the acts that are sunnat-i ghayr-i muakkada or mustahab is makrûh tanzîhî.