Is it permissible to act upon the predominant assumption by washing one or two out of five garments, when one of them is certainly known to be defiled, or is it obligatory to wash all of them, for a person afflicted with obsessive doubts (waswasa)?

If you are certain that one of five garments is impure, some scholars hold that it is obligatory to pray a number of times equal to the number of impure garments, plus one additional prayer to ensure praying in a pure garment. For example, if you are certain of the impurity of one garment, you would pray twice. Others preferred acting upon investigation (taharrī) and praying only once with the garment presumed to be pure, which is easier, especially for those afflicted with obsessive whispers (waswasah). This is what Sheikh al-Islam chose: that one prays in the garment most likely pure and avoids what is most likely impure unless it has been purified, knowing that purifying garments is only obligatory for the purpose of prayer.