Third: Impure. It consists of water whose properties have been altered by an impure substance, and any small quantity that has come into contact with impurity other than at the very place where that impurity is being washed away.

It can be purified by adding a large volume of water; and a large volume becomes pure once its alteration disappears on its own, or after some of it has been scooped out so that a large amount (1) still remains.

If the water reaches two qullahs (2)—that is (3) four hundred Egyptian ratls plus six and four-sevenths of a ratl—it is not rendered impure unless its characteristics change.

If a person doubts whether water, or anything else, has become impure (4), he holds to what is certain. When purifying water is mixed up with impure water so that the two cannot be told apart, he does not investigate but performs dry ablution for lack of other water. If it is confused with water that is pure yet non-purifying, he performs a single ablution, taking one handful from each.

If garments that are pure become indistinguishable from those that are impure, he prays in a number of garments equal to the number of impure ones and then adds one further prayer; the same ruling applies to cramped places. In a spacious area he may pray without investigation.

Section
[On Vessels]

All vessels, even costly ones, are permissible to use—except vessels of gold or silver and those plated with them—unless the vessel is merely banded (5) with a small amount of silver out of necessity.