I say, and with God's success: First: Water, even if it has been used: It is a condition for the permissibility of removing impurity with water that it be pure. Second: Liquids other than water: It is a condition for the permissibility of removing impurity with them that the liquid be pure, flowing, and capable of removing the impurity; thus, impurity cannot be removed with butter, milk, or oil; because although they are pure, they are not capable of removing impurity. Third: Rubbing with shoes or sandals, if there is a substance of impurity, and even if there is no substance, like urine, it cannot be purified except by washing. Fourth: Scrubbing: This applies to dry semen that has affected clothing and the body according to the apparent narration, and it includes the semen of both men and women; however, wet semen cannot be purified except by washing; as narrated by Al-Daraqutni in his Sunan from Aisha, may Allah be pleased with her, who said: "I would scrub the semen from the garment of the Messenger of Allah (peace be upon him) when it was dry, and I would wash it when it was wet." Fifth: Wiping: This applies to polished items such as mirrors, knives, swords, glass, nails, and other things that are not rough; if it is engraved, it does not purify, and there is no difference whether the impurity present on it has a substance or not, whether it is wet or dry, and whether the wiping is done with dirt, wool, grass, or a cloth or similar. Sixth: Dryness: The earth is purified by drying it with the sun and wind; as Abu Qilabah said: "The drying of the earth is its purification," and everything connected to it is purified: such as trees, walls, and the covering on roofs made of reeds and tiles, and the bricks built; these things are purified by drying according to the preferred opinion, and it is permissible to pray on them; because they are connected to the earth and take its ruling, but it is not permissible to perform tayammum with them. Seventh: Fire: Everything that is burned by fire is purified, and fire serves to purify impurity whether it is used for burning or cooking; for example, if the head of a sheep stained with blood is burned, it is purified and its broth is eaten. Eighth: Transformation or change of substance: Like oil if it becomes impure and is made into soap, and wine if it becomes vinegar, and a pig or donkey that falls into salt and becomes salt, and excrement if buried in a place and becomes ash; through transformation, musk becomes pure and fragrant even though it is originally the blood of a deer, and amber and civet— which is dirt that gathers under the tail of a cat— are also purified by transformation; all of these are purified by transformation due to the change of substance and becoming something else. Ninth: Carving wood, digging the ground, and the hollowing out of a mouse if it dies in solid fat; the Prophet (peace be upon him) was asked about a mouse that dies in fat, and he said: "If it is solid, throw away the mouse and what is around it, and eat the rest, but if it is liquid, no." Tenth: Tanning the skin of a dead animal: Tanning is the removal of the foul smell and the impure moisture from the skin, and all skins that can be tanned are purified by tanning, and it is permissible to pray on them, whether the tanner is a Muslim or a non-Muslim, and whether the tanning is real with chemicals, or legal by dusting, or sunning, or exposure to air. Eleventh: Slaughtering in its place by its people: Slaughtering linguistically means killing, and legally it means letting out the impure blood; as narrated by Rafi' ibn Khadij, may Allah be pleased with him, who said: The Messenger of Allah (peace be upon him) said: "... Whatever spills blood and mentions the name of Allah, eat it..." The rule for purification by slaughtering is that everything whose skin is purified by tanning, its skin and flesh are purified by slaughtering, even if its flesh is not eaten, and whatever does not have its skin purified by tanning is not purified by slaughtering, and it is a condition for the slaughter that purifies the skin and flesh that it be done by its people, meaning that a Muslim or a person of the Book slaughters without intentionally omitting the name (of Allah) according to the apparent opinion. Twelfth: Separation or division of the ideal: This is when a group of red ants urinate on wheat that they are trampling, so it is divided, or some is washed, or some is gifted, or some is sold, then each part is pure; because each part can potentially have the impurity in the other, so this possibility is considered in purification due to necessity, thus it is permissible to benefit from all of it due to doubt, even if collected, impurity returns. Thirteenth: Dilution: This applies to every liquid that is added to it from its pure kind until it overflows onto the ground, and liquids such as butter, oil, and fat are purified by pouring water over them three times and then lifting it off, while other liquids such as honey and syrup are purified by pouring water over them three times and boiling them until they return to their original state. Fourteenth: Concealment: This is when a metal that has been soaked with impurity is placed in fire until it becomes like embers, then it is extinguished with pure water three times while drying. Fifteenth: Shearing: This purifies wool and cotton. Sixteenth: Deepening: This applies to a well if no trace of impurity remains, or after drawing water after removing the impurity from it. See: Al-Waqayah p. 131, and Fath Bab Al-'Inayah 1: 245, and Allah knows best.