Ruling 14. Kurr water is an amount of water that fills a container with dimensions [i.e. length, breadth, and depth] totalling thirty-six cubic hand spans,[1] which is equivalent to approximately 384 litres.

Ruling 15. If an intrinsic impurity (ʿayn al‑najāsah) – such as urine or blood – or something that has become impure (mutanajjis) – such as impure clothing – comes into contact with kurr water, in the event that kurr water acquires the smell, colour, or taste of that impurity, it becomes impure; but if the kurr water does not change [in its smell, colour, or taste], it does not become impure.

Ruling 16. If the smell, colour, or taste of kurr water changes by means of something that is not impure, it does not become impure.

Ruling 17. If an intrinsic impurity like blood comes into contact with water that is more than kurr and changes part of its smell, colour, or taste, in the event that the amount that has not changed is less than kurr, all the water becomes impure. If [the amount that has not changed] is equal to kurr or more, only the amount that has changed its smell, colour, or taste is impure.

Ruling 18. The water of a fountain that is connected to kurr water purifies impure water. However, if it falls on impure water drop by drop, it does not purify it unless something is held over the fountain so that before the water begins to fall drop by drop, it connects to the impure water; and for the fountain water to purify the impure water, it must mix with the impure water.

Ruling 19. If an impure object is washed under a tap that is connected to kurr water, the water that drips from the object is pure (ṭāhir) if it is connected to kurr water and has not acquired the smell, colour, or taste of the impurity and does not contain an intrinsic impurity.

Ruling 20. If some part of kurr water freezes and the remaining water does not amount to kurr, in the event that an impurity comes into contact with it, it becomes impure; and however much of the ice melts is also impure.

Ruling 21. With regard to water that had been equivalent to kurr, if one doubts whether it has become less than kurr or not, it is to be treated as kurr water, meaning that it can still purify an impure object and if an impurity makes contact with it, it does not become impure [as long as its smell, colour, or taste does not change]. As for water that had been less than kurr, if one doubts whether it has become equal to kurr or not, it is ruled to be (i.e. it has the ḥukm of) less than kurr.

Ruling 22. There are two ways to establish that a quantity of water is kurr:

1. one is certain (i.e. he has yaqīn) or confident (i.e. he has iṭmiʾnān) about it, even if that is because of what someone has said;

2. two dutiful (ʿādil) men report it as so. If one dutiful or trustworthy person, or someone who has possession of the kurr water, reports it as so but his report does not give one confidence as to it being true, then based on obligatory precaution (al‑iḥtiyāṭ al‑wājib), the water being kurr will not be established.