226 - Issue: He said: "And if the location of the impurity on the garment is hidden, one should exercise extra caution until one is certain that the washing has covered the impurity."

The summary of this is that if an impurity is hidden on one's body or garment and one intends to pray in it, it is not permissible for one to do so until one is certain of its removal. This certainty is not attained until one washes every area that could possibly have been touched by the impurity. If one does not know the area on the garment, one must wash it all. If one knows it is on one of its two sides, one must wash that entire side. If one sees it on one's body or a garment one is wearing, one must wash everything within one's sight of it. This is the opinion of al-Nakha'i, al-Shafi'i, Malik, and Ibn al-Mundhir. 'Ata', al-Hakam, and Hammad said: If the impurity is hidden in the garment, one should sprinkle water (nadḥ) over all of it. Ibn Shubruma said: One should perform ijtihad to determine the location of the impurity and wash it. They may cite as evidence the hadith of Sahl ibn Hunayf from the Prophet (peace and blessings of Allah be upon him) regarding madhy (prostatic fluid), in which he said: I said, "O Messenger of Allah, what about what has touched my garment from it?" He said, "It is sufficient for you to take a handful of water and sprinkle it where you think it has touched it." Thus, he commanded him to use ijtihad and sprinkling. Our evidence is that he is certain of the presence of an impediment to prayer, so prayer is not permitted for him except with certainty of its removal, just like someone who is certain of having committed hadath (ritual impurity) but is doubtful about purification. Furthermore, sprinkling does not remove impurity, and the hadith of Sahl concerns madhy specifically, not other things, so it cannot be generalized because the rulings on impurities differ. His statement, "where you think it has touched it," is interpreted as applying to one who thinks it touched a side of his garment without certainty, so sprinkling or washing that location is sufficient.

Section: If an impurity is hidden in a wide open space, one may pray wherever one wishes, and it is not obligatory to wash all of it, because that would be a hardship. If one were forbidden from praying, it would lead to not finding a place to pray. However, if it is a small place, such as a room or similar, one must wash all of it, because washing it does not entail hardship, so it is analogous to a garment.