37. If rain falls once upon a najis object which does not contain any ayn al-najÁsah, the areas which come in contact with the rain will become ÔÁhir. It is also not necessary to wring carpets, clothes or other similar items. However, if only a few droplets of rain fall, it will be of no (canonical) benefit. Rather it should rain in such a manner that one should be able to say, “it is raining.” In fact, based on obligatory precaution, it should rain in such a quantity that if it falls on a hard surface, the water starts to flow on it.
38. If rain water falls on an ayn al-najÁsah and splashes elsewhere, and if the ayn al-najÁsah is not found in the water, nor does it acquire the smell, colour or taste of the najÁsah, then that water is ÔÁhir. So, if it rains on blood and then splashes, and particles of blood are seen in the water, or it acquires the smell, colour or taste of blood, it is najis.
39. If there is ayn al-najÁsah on the roof of a building, the water that flows down from the roof or the drain spout after contacting the najis object will be deemed ÔÁhir as long as the rain continues to fall on the roof. After the rain stops falling, if it is known that the water that is flowing down has contacted a najis item, it will be najis.
40. A najis earth or ground on which rain falls becomes ÔÁhir, and if it begins flowing on the ground, and reaches a najis area under the roof while it is still raining, it makes that area ÔÁhir as well.
41. If rain water falls on najis dust and – before becoming mudhaf - soaks it, it becomes ÔÁhir even though it may have turned into mud due to the rain.
42. If rain water gathers in a place, even if its quantity is less than kurr, and a najis thing is washed in it while it is raining, it becomes ÔÁhir provided its smell, colour or taste does not change due to the najÁsah.
43. If it rains on a ÔÁhir carpet which is spread over a najis ground, and if the water seeps onto the najis ground, the carpet does not become najis. In fact, the ground also will become ÔÁhir.
44. If rain water gathers in a hole and its quantity is less than kurr, it will become najis if a najis object contacts it after it has stopped raining.