The sun
192. The sun makes the earth, building, and the walls Pak, provided the following five conditions are fulfilled:
The najis thing should be sufficiently wet, and if it is dry, it should be made wet so that the sun dries it up.
If the Najisul Ayn is present on that thing, it should be removed from it before it is dried by the sun.
Nothing should intervene between the najis thing and the sun. Therefore, if the rays fall on the najis thing from behind a curtain etc, or a cloud, and makes it dry, the thing will not become Pak. But, there is no harm if the cloud is so thin that it does not serve as an impediment, between the najis thing and the sun.
Only the sun should make the najis thing dry. So, if a najis thing is jointly dried by the wind and the sun, it will not become Pak. However, it would not matter if the wind blows lightly, and it may not be said that it has had any share in making the najis thing dry.
The sun should dry up the whole najis part of the building all at once. If the sun dries the surface of the najis earth, or building, first, and later on dries the inner part, only the surface will become Pak, and the inner portion will remain najis.
193. A najis mat will be made Pak by the sun, but if it is woven with threads, then the threads becoming Pak is a matter of Ishkal. Similarly, the sun does not, in all probabilities, make Pak the trees, the grass, the doors and the windows.
194. If the sun shines on najis earth, and one doubts later whether
the earth was wet or not at that time, or whether the wetness dried up because
of the sunshine or not, the earth will remain najis.
Similarly, if one doubts whether Najisul Ayn had been removed from the earth
before sunshine, or whether there was any impediment preventing direct sunshine,
the earth will remain najis.
195. If the sun shines on one side of a najis wall and as a consequence of it, the other side of the wall also dries up, then both the sides will be considered Pak.