What are the categories of impurity, what are examples of them, and what is required to clean each one?

Impurity is divided into two types: intrinsic and circumstantial. Intrinsic impurity is the essence of the impure substance itself, such as urine, and it cannot be purified by water unless it undergoes a transformation. As for circumstantial impurity, it is that which affects a pure object and can be purified by washing.

Circumstantial impurities are divided into three categories based on their severity: 1. Light impurity: Such as the urine of an infant boy who has not yet eaten food. This is purified by sprinkling water over it until it covers the affected area. 2. Medium impurity: Such as human urine and feces, and most other impurities. This is purified by washing with water until the impurity is removed; the persistence of the color does not matter. 3. Heavy impurity: This is the impurity of a dog. It is purified by washing the affected area seven times, the first of which is with earth.

As for how to purify objects that become impure: 1. Earth: If there is a visible substance, it should be removed. Then, water is poured over the impure spot until its trace disappears. Alternatively, it can be covered with pure earth if water is not available. 2. Water: Impure water is purified by cleaning it until the trace of impurity in its color, taste, or smell disappears, whether by sprinkling, by self-purification, by adding a large quantity of water, or by modern purification methods. 3. Clothes and furnishings: They are washed with water or detergents until the trace of impurity disappears. Impure sandals and leather socks (khuff) are purified by rubbing them on the ground. 4. Utensils: They are washed with water or detergents until the trace of impurity disappears.