Shafaqna (International Shia News Agency) – The Grand Ayatollah Sistani answered some questions regarding purity .According to Shafaqna the questions and answers are as follows:
Question: What about the leather products made in a European country, if we are unaware of the source of that leather? It is said that some European countries import cheap leather from Muslim countries and then use it for manufacturing various products. Can we consider such leather pure? Are we allowed to say salat in them? Can such a weak probability [about it originating from a Muslim country] be given any credence?
Answer: If the probability of the leather originating from a zabiha (an animal slaughtered Islamically) source is so weak that people would not normally give any credence (for example, the probability of 2%), it is to be considered impure and this cannot be used in salat. But if the probability is not so weak, it can be considered pure and using it in salat would be permissible.
Question: In the West, there are many public laundry places in which Muslims and non-Muslims wash their clothes. Is it permissible for us to pray in the clothes washed in such facilities, especially when we have no knowledge whether or not the washing machines are connected to the kurr water2 at some stages of the washing, and whether or not it purifies the clothes in the process of washing?
Answer: There is no problem in praying in those clothes that were pure before washing them [in such facilities] as long as you are not aware that they have become impure. [In other words, what goes in the public washing machine as pure comes out as pure unless you are sure that it has become impure.]
Similarly, [you can pray in] the impure clothes [that were washed in the public laundry machines] provided that you are reassured:
that the impure element, if any, has been washed away;
that the pure water covered the entire impure area twice (if it had become impure by urine and even if the water was connected to kurr source as an obligatory precaution) or just once (if it had become impure by other elements);
and that the water was removed from the clothes by wringing or other similar method [i.e., spinning of the machine] if it was qalil.
However, if you are not sure and just have conjecture that the garment has been purified as per religious requirement, the previously impure garment will still be considered impure and praying in it would not be valid.
Question: The floor of most houses in the West is covered with carpet which is glued to the floor in such a way that it is difficult to lift it off. How can such a carpet be rendered pure (tahir), if it becomes impure with urine or blood? The water used to purify in both the cases could be qalil or kathir. Please explain the ruling in both cases.
Answer: If it is possible to wipe the water off the carpet by using a piece of cloth or a vacuum cleaner, it can be purified with qalil water, provided that the water is wiped off the carpet, in the process. Conversely, it must be purified by kathir water [i.e., by using a hose pipe connected to the tap].
Question: Can Muslim, who rents a fully furnished house in the West, consider everything in it to be ritually pure as long as he does not find any trace of impure things in it, even if the previous occupant was from Ahlul Kitab, i.e., a Christian or a Jew? What if the previous occupant was a Buddhist or an atheist who does not believe in God and the prophets?
Answer: Yes, he can consider everything in the house ritually pure as long as he does not know that it has become impure. Just conjecture or doubt about impurity is of no value.
Question: If a dog licks my body or clothes, how should I purify it?
Answer: It is sufficient to wash it once. However, if the water is little, it is necessary to rid it of the water by wringing.
Question: The earth is one of the purifying agents. Following the example of a shoe’s sole that can be purified by walking on the earth, would the same rule apply to car tires?
Answer: The earth cannot purify the tires.
Question: I am living in India and I have a lot of doubts about things I am using and I eating. What is my duty about such things?
Answer: A well known religious law says: “Everything is ritually pure for you unless you come to know that it is ritually impure.” This law declares everything to be pure unless one becomes sure a particular item has become impure. And as long as you are not sure that it has become ritually impure (najis), it is to be considered pure and you can apply all the rules of purity to it without any hesitation or doubt.
Question: What is the hokm (ruling) about Ahlul Kitab (people of the Book)? Are they clean? How should we deal with them?
Answer: The Ahlul Kitab (that is, the Jews, the Christians and the Zoroastrians) are ritually pure (tahir) as long as you do not know that they have become ritually impure (najis) by coming into contact with an impure object. You can follow this ruling when dealing with them.
Source: Ayatollah Sistani