a. The najis thing should be wet. Therefore, if it is not wet, it should be made wet so that the sun can make it dry.
b. If the ayn al-najÁsah is on the thing, it should be removed before the sun makes the najis thing dry.
c. Nothing should obstruct the sunlight from directly falling on the thing. Therefore, if the sunlight falls on the object from behind a curtain, or the clouds or any similar impediment, and makes the najis thing dry, it will not become ÔÁhir. However there is no harm if the impediment is thin enough that it does not serve to obstruct the sunlight.
d. Only the sun should make the najis thing dry. Thus, if the najis thing is made dry by the wind and the sun, it will not become ÔÁhir. However there if no harm if a light wind blows over the thing, such that it cannot be said that it aided in drying it.
e. If the najÁsah has penetrated a building or a structure, the sun should make it all—the surface and the interior—dry at once. Therefore, if it shines on a najis ground or building and makes its surface dry, and then shines upon it once again, making its interior dry, only the surface will be ÔÁhir and the interior part will remain najis.