How to Purify Women’s Abayah If It Passes over Impurity
Question

The female Companions complained that their Jilbabs would get dirty, and the Prophet (blessings and peace of Allah be upon him) said: “It is purified by what comes after it.” 
Nowadays, if we walk in the streets and pass over something wet which is impure, then carry on walking over asphalt or we get in a car, does this purify the Abayah? 
My question is: what is it that purifies the Abayah – is it the dust, the mere act of walking over dry ground, or what?
Praise be to Allah.The issue of removing impurity on clothes is one of the issues concerning which there is a well-known difference of opinion among the scholars. 
The majority of scholars are of the view that if impurity is found on a garment or shoe, then it can only be purified by removing the impurity with water. 
The Hanafis (may Allah have mercy on them) are of the view that whatever method is used to remove the impurity, that is sufficient. Shaykh Al-Islam Ibn Taymiyyah (may Allah have mercy on him) and a number of our contemporary scholars agreed with them, and that is the correct view.
It was narrated from a concubine of Ibrahim ibn `Abd Ar-Rahman ibn `Awf (may Allah have mercy on him), that she asked Umm Salamah (may Allah be pleased with her), the wife of the Prophet (blessings and peace of Allah be upon him): I am a woman whose garment drags, and I may walk through a dirty place. Umm Salamah (may Allah be pleased with her) said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “That which comes after it purifies it.” (Narrated by At-Tirmidhi (143), Abu Dawud (383) and Ibn Majah (531). The Hadith was classed as authentic by Shaykh Al-Albani in Sahih At-Tirmidhi)
Abu Sa`id Al-Khudri (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “When one of you comes to the mosque, let him look and if he sees any dirt or filth on his shoes, let him wipe it off and pray wearing them.” (Narrated by Abu Dawud (650); classed as authentic by Al-Albani in Sahih Abu Dawud)
In these two Hadiths, the Prophet (blessings and peace of Allah be upon him) instructed people to remove impurity by means other than water.
Shaykh Al-Islam Ibn Taymiyyah (may Allah have mercy on him) said:
“The Sunnah enjoins using water in the Prophet’s words to Asma’: “Scratch it off, then rub it, then wash it with water .” Narrated by Al-Bukhari and Muslim; and his words concerning the vessels of the Magians: “Rub them, then wash them with water.” – Narrated by At-Tirmidhi, Abu Dawud and Ibn Majah with an authentic Isnad (chain of narrators).
This applies to the vessels of the People of the Book, not the Magians – And what he said in the Hadith about the Bedouin who urinated in the mosque: “Pour a bucket of water over his urine.” (Al-Bukhari and Muslim). So he enjoined removing the impurity with water in specific cases, but he did not issue general instructions to remove every impurity with water.
In some cases, he gave permission to remove it with something other than water, such as the following:

Cleaning oneself with pebbles after relieving oneself.
His words with regard to shoes: “Then rub them in the dust, for the dust is a means of purification for them.” (Narrated by Abu Dawud and classed as authentic by Al-Albani)
His words concerning the dragging hem of a garment: “That which comes after it purifies it.”
Dogs used to come and go and urinate in the mosque of the Messenger of Allah (blessings and peace of Allah be upon him), then they did not wash that away. (Narrated by Al-Bukhari)
The Prophet (blessings and peace of Allah be upon him) said concerning cats: “They are among those who go around among you.” (Narrated by At-Tirmidhi, Abu Dawud, An-Nasai and Ibn Majah with an authentic Isnad) Even though cats usually eat mice, and there were no streams from which they would drink to cleanse their mouths with water; rather their purification is their saliva .
Wine that turns into vinegar by itself becomes pure, according to the consensus of the Muslims.

As that is the case, the more correct view regarding this matter is that if impurity is removed by any means, the ruling on it ceases to be in effect. If the ruling is confirmed for a reason, it no longer applies when that reason is no longer present. But it is not permissible to use food and drink to remove impurities unnecessarily, because that is a waste of money. By the same token, it is not permissible to use them to clean oneself after relieving oneself.
Those who say that it can only be removed with water include some who say that this is an act of worship. But that is not the case. The Lawgiver (Allah) enjoined using water in specific cases when nothing else will do, because using drinks from which the Muslims may benefit would spoil those drinks, and removing the impurity with solid items is not possible, such as removing impurity by washing a garment or a vessel or the ground with water, because it is known that if they had rosewater, vinegar and the like, they are not commanded to spoil them, so how about if they do not have them.
Some of them said that water has softness that other liquids do not have, so other liquids cannot achieve the same results. But that is not the case; rather vinegar, rosewater and other liquids may remove impurities in vessels as water does, and may be more effective." (Majmu` Al-Fatawa  21/474-476)
From the above, it is clear that if the woman who gets some impurity on the hem of her garment then walks over ground or asphalt or a street or a pavement that removes the essence of that impurity, so that no trace of it is left, then her garment is purified by that, and she does not have to use water in order to remove that impurity.
And Allah knows best.