The Assumption That Everything is Tahir Until Proven Otherwise

Everything is tahir until proven najis, and doubt about something being najis is not enough to make it najis

"[W]e should start with the assumption that everything is tahir and halal unless we come to know otherwise." (Sayyid Muhammad Rizvi)

"Principle number one: Everything is tahir. If, however, you become doubtful whether it is still the case, you should rule out your doubt, i.e. it remains tahir. Principle number two: Any thing that was najis, and you are not sure whether you made it tahir, remains najis. Principle number three: Anything you do not have prior knowledge as to its state, i.e. being tahir or najis, it should now be considered tahir." (


Proving something to be najis requires one to reach certainty, and a merely high probability of something has become najis is not enough for proof

Ruling 115. There are three ways to establish the impurity of an object: one is certain, or is confident by rational means, that the object is impure. If one only supposes (i.e. has a ẓann) that an object is impure, it is not necessary for him to avoid it [i.e. it is not ruled as being impure]. Therefore, there is no problem in eating in cafés and in guesthouses where the people who eat there are unconcerned about religious matters and who do not observe laws relating to what is pure and what is impure, as long as one is not confident that the food brought to him is impure; (

“The utensils of the mushrikin and other kuff”ar are to be considered tahir as long as it is not known that they have touched them with flowing wetness. [This rule is valid] provided the utensils are not made from leather, otherwise they will be considered najis unless it is known that the animal [from which the leather originated] had been slaughtered Islamically or that it had been in possession of a Muslim [before coming into the kafir's possession]. (Sayyid Muhammad Rizvi) (Quoting Urwatal Wuthaqa)

"What is obtained from the hands of the kafirs -like bread, oil, honey and other similar things, whether they are liquid or solid- is tahir unless you come to know that they have touched it with flowing wetness. The same applies to their clothes and utensils. And conjecture about najasat [in such cases] should not be taken into account.” (Sayyid Muhammad Rizvi) (Quoting Sayyed al Khoei)

[2/95] al-Istibsar: From al-Mufid from Ja’far b. Muhammad from his father from Sa’d b. Abdallah from Ahmad b. Muhammad from al-Hasan b. Mahbub from Abdallah b. Sinan who said: my father asked Abi Abdillah عليه السلام while I was present [the following question]: I sometimes lend my clothes to a Dhimmi and I know that he drinks wine and eats the meat of swine, so when he returns them to me should I wash them before praying in them? Abu Abdillah عليه السلام said: pray in them and do not wash them because of that, for you lent them to him while you were certain that they were pure and you do not have certainty about its impurity (when he returns them), so there is no harm in you praying in it until you become certain that it is impure. (Mu'jam al Hadith al Mu'tabara)