Sheikh Yûsuf al-Qâsim
`Aishah said: “None of us had more than a single garment and we used to have our menses while wearing it. Whenever it got soiled with blood of menses we used to apply saliva to the blood spot and rub off the blood with our nails.” [Sahîh al-Bukhârî]
This hadîth is authentic. As discussed by Ibn Hajr al-`Asqalânî in his commentary on this hadîth, it is used as evidence by those who say that impurities can be removed by any pure liquid, including saliva. [Fath al-Bârî (1/331)]
This is the opinion of Abû Hanîfah and Abû Yûsuf. [al- Hidâyah ma` Fath al-Qadîr (1/169-170)]
With respect to the Hanbalî school of thought, this opinion has been narrated from Ahmad b. Hanbal [al-Insâf (2/298)]. It was subsequently adopted by Ibn Taymiyah who said: “The most authentic opinion is that regardless of how the removal of an impurity is achieved, the ruling of impurity will also be removed, since any legal ruling that is established by a certain cause will cease to be in effect when the cause for it is removed.” [Majmû` al-Fatâwâ (21/475)]
This is the strongest saying on this issue. Whoever wishes to adopt the opinion of the majority that impurities can never be removed by other than water, we say that he may do so. There is room in such matters for more than one opinion; may Allah be praised.
And Allah knows best.
Source: Islam Today